Trajan (/ˈtreɪdʒən/; Latin: Imperator Caesar Nerva Traianus Divi Nervae filius Augustus;^[1][2] 18 September 53 – 8 August 117) was Roman emperor from 98 to 117. Officially declared by the Senate optimus princeps ("the best ruler"), Trajan is remembered as a successful soldier-emperor who presided over the greatest military expansion in Roman history, leading the empire to attain its maximum territorial extent by the time of his death. He is also known for his philanthropic rule, overseeing extensive public building programs and implementing social welfare policies, which earned him his enduring reputation as the second of the Five Good Emperors who presided over an era of peace and prosperity in the Mediterranean world.

Trajan was born in the city of Italica (close to modern Sevilla, Spain) in the province of Hispania Baetica. Although misleadingly designated by some later writers as a provincial, his family came from Umbria and he was born a Roman citizen. ^[3] Trajan rose to prominence during the reign of emperor Domitian. Serving as a legatus legionis in Hispania Tarraconensis, in 89 Trajan supported Domitian against a revolt on the Rhine led by Antonius Saturninus. In September 96, Domitian was succeeded by the old and childless Nerva, who proved to be unpopular with the army. After a brief and tumultuous year in power, culminating in a revolt by members of the Praetorian Guard, he was compelled to adopt the more popular Trajan as his heir and successor. Nerva died in 98 and was succeeded by his adopted son without incident.

As a civilian administrator, Trajan is best known for his extensive public building program, which reshaped the city of Rome and left numerous enduring landmarks such as Trajan's Forum, Trajan's Market and Trajan's Column. Early in his reign, he annexed the Nabataean Kingdom, creating the province of Arabia Petraea. His conquest of Dacia enriched the empire greatly, as the new province possessed many valuable gold mines.

Trajan's war against the Parthian Empire ended with the sack of the capital Ctesiphon and the annexation of Armenia and Mesopotamia. His campaigns expanded the Roman Empire to its greatest territorial extent. In late 117, while sailing back to Rome, Trajan fell ill and died of a stroke in the city of Selinus. He was deified by the Senate and his ashes were laid to rest under the Column. He was succeeded by his cousin Hadrian, whom Trajan supposedly adopted on his deathbed.

As an emperor, Trajan's reputation has endured – he is one of the few rulers whose reputation has survived nineteen centuries. Every new emperor after him was honoured by the Senate with the wish felicior Augusto, melior Traiano (that he be "luckier than Augustus and better than Trajan"). Among medieval Christian theologians, Trajan was considered a virtuous pagan. In the Renaissance, Machiavelli, speaking on the advantages of adoptive succession over heredity, mentioned the five successive good emperors "from Nerva to Marcus"^[4] – a trope out of which the 18th-century historian Edward Gibbon popularized the notion of the Five Good Emperors, of whom Trajan was the second.^[5]

As far as ancient literary sources are concerned, an extant continuous account of Trajan's reign does not exist. An account of the Dacian Wars, the Commentarii de bellis Dacicis, written by Trajan himself or a ghostwriter and modelled after Caesar's Commentarii de Bello Gallico, is lost with the exception of one sentence. Only fragments remain of the Getiká, a book by Trajan's personal physician Titos Statilios Kriton. The Parthiká, a 17-volume account of the Parthian Wars written by Arrian, has met a similar fate.^[6] Book 68 in Cassius Dio's Roman History, which survives mostly as Byzantine abridgments and epitomes, is the main source for the political history of Trajan's rule.^[7] Besides this, Pliny the Younger's Panegyricus and Dio of Prusa's orations are the best surviving contemporary sources. Both are adulatory perorations, typical of the late Roman era, that describe an idealized monarch and an equally idealized view of Trajan's rule, and concern themselves more with ideology than with actual fact.^[8] The tenth volume of Pliny's letters contains his correspondence with Trajan, which deals with various aspects of imperial Roman government, but this correspondence is neither intimate nor candid: it is an exchange of official mail, in which Pliny's stance borders on the servile.^[9] It is certain that much of the text of the letters that appear in this collection over Trajan's signature was written and/or edited by Trajan's Imperial secretary, his ab epistulis.^[10] Therefore, discussion of Trajan and his rule in modern historiography cannot avoid speculation, as well as recourse to non-literary sources such as archaeology and epigraphy.^[11]

Marcus Ulpius Traianus was born on 18 September 53 AD in the Roman province of Hispania Baetica^[12] (in what is now Andalusia in modern Spain), in the city of Italica (now in the municipal area of Santiponce, in the outskirts of Seville). Although frequently designated the first provincial emperor, and dismissed by later writers such as Cassius Dio (himself of provincial origin) as "an Iberian, and neither an Italian nor even an Italiot", Trajan appears to have hailed on his father's side from the area of Tuder (modern Todi) in Umbria, at the border with Etruria, and on his mother's side from the Gens Marcia, of an Italic family of Sabine origin. Trajan's birthplace of Italica was founded as a Roman military colony of Italian settlers in 206 BC, though it is unknown when the Ulpii arrived there. It is possible, but cannot be substantiated, that Trajan's ancestors married local women and lost their citizenship at some point, but they certainly recovered their status when the city became a municipium with Latin citizenship in the mid-1st century BC.^{[13] [3]}

Trajan was the son of Marcia, a Roman noblewoman and sister-in-law of the second Flavian Emperor Titus,^[14] and Marcus Ulpius Traianus, a prominent senator and general from the gens Ulpia. Marcus Ulpius Traianus the elder served Vespasian in the First Jewish-Roman War, commanding the Legio X Fretensis.^[15] Trajan himself was just one of many well-known Ulpii in a line that continued long after his own death. His elder sister was Ulpia Marciana, and his niece was Salonina Matidia. The patria of the Ulpii was Italica, in Spanish Baetica.^[12]

As a young man, he rose through the ranks of the Roman army, serving in some of the most contested parts of the Empire's frontier. In 76–77, Trajan's father was Governor of Syria (Legatus pro praetore Syriae), where Trajan himself remained as Tribunus legionis. From there, after his father's replacement, he seems to have been transferred to an unspecified Rhine province, and Pliny implies that he engaged in active combat duty during both commissions.^[16] In about 86, Trajan's cousin P. Aelius Afer died, leaving his young children Hadrian and Paulina orphans. Trajan and a colleague of his, Publius Acilius Attianus, became co-guardians of the two children.^[17]

In 91, Trajan was created ordinary Consul for the year, which was a great honour as he was in his late thirties and therefore just above the minimum legal age (32) for holding the post. This can be explained in part by the prominence of his father's career, as his father had been instrumental to the ascent of the ruling Flavian dynasty, held consular rank himself and had just been made a patrician.^[18] Around this time Trajan brought Apollodorus of Damascus with him to Rome.^[19] and also married Pompeia Plotina, a noble woman from the Roman settlement at Nîmes; the marriage ultimately remained childless.^[20]

It has been remarked by many authors (among them Trajan's late successor Julian) that Trajan was personally inclined towards homosexuality, far in excess of the usual bisexual activity that was common among upper class Roman men of the period. Although Julian's scathing comments on the matter^[21] reflect a change of mores that began with the Severan dynasty,^[22] an earlier author, Cassius Dio, already makes reference to Trajan's marked personal preference for the male sex. Trajan's putative lovers included Hadrian, pages of the imperial household, the actor Pylades, a dancer called Apolaustus, and senator Lucius Licinius Sura.^[21]

As the details of Trajan's military career are obscure, it is only sure that in 89, as legate of Legio VII Gemina in Hispania Tarraconensis, he supported Domitian against an attempted coup.^[23] Later, after his 91 consulate (held with Acilius Glabrio, a rare pair of consuls at the time, in that neither consul was a member of the ruling dynasty), he held some unspecified consular commission as governor on either Pannonia or Germania Superior – possibly both. Pliny – who seems to deliberately avoid offering details that would stress personal attachment between Trajan and the "tyrant" Domitian – attributes to him, at the time, various (and unspecified) feats of arms.^[24]

Since Domitian's successor, Nerva, was unpopular with the army and had just been forced by his Praetorian Prefect Casperius Aelianus to execute Domitian's killers,^[25] he felt the need to gain the support of the military in order to avoid being ousted. He accomplished this in the summer of 97 by naming Trajan as his adoptive son and successor, allegedly solely on Trajan's outstanding military merits.^[24] There are hints, however, in contemporary literary sources that Trajan's adoption was imposed on Nerva. Pliny implied as much when he wrote that, although an emperor could not be coerced into doing something, if this were the way in which Trajan was raised to power, then it was worth it. If this was what actually occurred, Trajan would be a usurper, and the notion of a natural continuity between Nerva's and Trajan's reigns would be an ex post fiction developed later by historians such as Tacitus.^[26]

According to the Augustan History, it was the future Emperor Hadrian who brought word to Trajan of his adoption.^[19] Hadrian was then retained on the Rhine frontier by Trajan as a military tribune, becoming privy to the circle of friends and relations with which Trajan surrounded himself – among them the then governor of Germania Inferior, the Spaniard Lucius Licinius Sura, who became Trajan's chief personal adviser and official friend.^[27] As a token of his influence, Sura would later become consul for the third time in 107. Some ancient sources also tell about his having built a bath named after him on the Aventine Hill in Rome, or having this bath built by Trajan and then named after him, in either case a signal of honour as the only exception to the established rule that a public building in the capital could be dedicated only to a member of the imperial family.^[28][29] These baths were later expanded by the third century emperor Decius as a means of stressing his link to Trajan.^[30] Sura is also described as telling Hadrian in 108 about his selection as imperial heir.^[31] According to a modern historian, Sura's role as kingmaker and éminence grise was deeply resented by some senators, especially the historian Tacitus, who acknowledged Sura's military and oratory virtues but at the same time resented his rapacity and devious ways, similar to those of Vespasian's éminence grise Licinius Mucianus.^[32]

As governor of Lower Germany during Nerva's reign, Trajan received the impressive title of Germanicus for his skillful management and rule of the volatile Imperial province.^[33] When Nerva died on 27 January 98, Trajan succeeded to the role of emperor without any outward incident. However, the fact that he chose not to hasten towards Rome, but instead to make a lengthy tour of inspection on the Rhine and Danube frontiers, hints to the possible fact that his power position in Rome was unsure and that he had first to assure himself of the loyalty of the armies at the front. It is noteworthy that Trajan ordered Prefect Aelianus to attend him in Germany, where he was apparently executed ("put out of the way"),^[34] with his post being taken by Attius Suburanus.^[35] Trajan's accession, therefore, could qualify more as a successful coup than an orderly succession.^[36]

On his entry to Rome, Trajan granted the plebs a direct gift of money. The traditional donative to the troops, however, was reduced by half.^[37] There remained the issue of the strained relations between the emperor and the Senate, especially after the supposed bloodiness that had marked Domitian's reign and his dealings with the Curia. By feigning reluctance to hold power, Trajan was able to start building a consensus around him in the Senate.^[38] His belated ceremonial entry into Rome in 99 was notably understated, something on which Pliny the Younger elaborated.^[39]

By not openly supporting Domitian's preference for equestrian officers,^[40] Trajan appeared to conform to the idea (developed by Pliny) that an emperor derived his legitimacy from his adherence to traditional hierarchies and senatorial morals.^[41] Therefore, he could point to the allegedly republican character of his rule.^[42] In a speech at the inauguration of his third consulship, on 1 January 100, Trajan exhorted the Senate to share the care-taking of the Empire with him – an event later celebrated on a coin.^[43][44] In reality, Trajan did not share power in any meaningful way with the Senate, something that Pliny admits candidly: "[E]verything depends on the whims of a single man who, on behalf of the common welfare, has taken upon himself all functions and all tasks".^[45][46] One of the most significant trends of his reign was his encroachment on the Senate's sphere of authority, such as his decision to make the senatorial provinces of Achaea and Bithynia into imperial ones in order to deal with the inordinate spending on public works by local magnates^[47] and the general mismanagement of provincial affairs by various proconsuls appointed by the Senate.^[48]

In the formula developed by Pliny, however, Trajan was a "good" emperor in that, by himself, he approved or blamed the same things that the Senate would have approved or blamed.^[49] If in reality Trajan was an autocrat, his deferential behavior towards his peers qualified him to be viewed as a virtuous monarch.^[50] The whole idea was that Trajan wielded autocratic power through moderatio instead of contumacia – moderation instead of insolence.^[51] In short, according to the ethics for autocracy developed by most political writers of the Imperial Roman Age, Trajan was a good ruler in that he ruled less by fear, and more by acting as a role model, for, according to Pliny, "men learn better from examples".^[52]

Eventually, Trajan's popularity among his peers was such that the Roman Senate bestowed upon him the honorific of optimus, meaning "the best",^[53][54] which appears on coins from 105 on.^[55] This title had mostly to do with Trajan's role as benefactor, such as in the case of him returning confiscated property.^[56]

That Trajan's ideal role was a conservative one becomes evident from Pliny's works as well as from the orations of Dio of Prusa – in particular his four Orations on Kingship, composed early during Trajan's reign. Dio, as a Greek notable and intellectual with friends in high places, and possibly an official friend to the emperor (amicus caesaris), saw Trajan as a defender of the status quo.^[57][58] In his third kingship oration, Dio describes an ideal king ruling by means of "friendship" – that is, through patronage and a network of local notables who act as mediators between the ruled and the ruler.^[59] Dio's notion of being "friend" to Trajan (or any other Roman emperor), however, was that of an informal arrangement, that involved no formal entry of such "friends" into the Roman administration.^[60]

As a senatorial Emperor, Trajan was inclined to choose his local base of political support from among the members of the ruling urban oligarchies. In the West, that meant local senatorial families like his own. In the East, that meant the families of Greek notables. The Greeks, though, had their own memories of independence – and a commonly acknowledged sense of cultural superiority – and, instead of seeing themselves as Roman, disdained Roman rule.^[61] What the Greek oligarchies wanted from Rome was, above all, to be left in peace, to be allowed to exert their right to self-government (i.e., to be excluded from the provincial government, as was Italy) and to concentrate on their local interests.^[62] This was something the Romans were not disposed to do as from their perspective the Greek notables were shunning their responsibilities in regard to the management of Imperial affairs – primarily in failing to keep the common people under control, thus creating the need for the Roman governor to intervene.^[63]

An excellent example of this Greek alienation was the personal role played by Dio of Prusa in his relationship with Trajan. Dio is described by Philostratus as Trajan's close friend, and Trajan as supposedly engaging publicly in conversations with Dio.^[64] Nevertheless, as a Greek local magnate with a taste for costly building projects and pretensions of being an important political agent for Rome,^[65] Dio of Prusa was actually a target for one of Trajan's authoritarian innovations: the appointing of imperial correctores to audit the civic finances^[66] of the technically free Greek cities.^[67] The main goal was to curb the overenthusiastic spending on public works that served to channel ancient rivalries between neighboring cities. As Pliny wrote to Trajan, this had as its most visible consequence a trail of unfinished or ill-kept public utilities.^[68]

Competition among Greek cities and their ruling oligarchies was mainly for marks of preeminence, especially for titles bestowed by the Roman emperor. Such titles were ordered in a ranking system that determined how the cities were to be outwardly treated by Rome.^[69] The usual form that such rivalries took was that of grandiose building plans, giving the cities the opportunity to vie with each other over "extravagant, needless ... structures that would make a show".^[70] A side effect of such extravagant spending was that junior and thus less wealthy members of the local oligarchies felt disinclined to present themselves to fill posts as local magistrates, positions that involved ever-increasing personal expense.^[71]

Roman authorities liked to play the Greek cities against one another^[72] – something of which Dio of Prusa was fully aware:

These same Roman authorities had also an interest in assuring the cities' solvency and therefore ready collection of Imperial taxes.^[75] Last but not least, inordinate spending on civic buildings was not only a means to achieve local superiority, but also a means for the local Greek elites to maintain a separate cultural identity – something expressed in the contemporary rise of the Second Sophistic; this "cultural patriotism" acted as a kind of substitute for the loss of political independence,^[76] and as such was shunned by Roman authorities.^[77] As Trajan himself wrote to Pliny: "These poor Greeks all love a gymnasium ... they will have to content with one that suits their real needs".^[78]

The first known corrector was charged with a commission "to deal with the situation of the free cities", as it was felt that the old method of ad hoc intervention by the Emperor and/or the proconsuls had not been enough to curb the pretensions of the Greek notables.^[79] It is noteworthy that an embassy from Dio's city of Prusa was not favorably received by Trajan,^[80] and that this had to do with Dio's chief objective, which was to elevate Prusa to the status of a free city, an "independent" city-state exempt from paying taxes to Rome.^[81] Eventually, Dio gained for Prusa the right to become the head of the assize-district, conventus (meaning that Prusans did not have to travel to be judged by the Roman governor), but eleutheria (freedom, in the sense of full political autonomy) was denied.^[82]

Eventually, it fell to Pliny, as imperial governor of Bithynia in 110 AD, to deal with the consequences of the financial mess wrought by Dio and his fellow civic officials.^[83] "It's well established that [the cities' finances] are in a state of disorder", Pliny once wrote to Trajan, plans for unnecessary works made in collusion with local contractors being identified as one of the main problems.^[84] One of the compensatory measures proposed by Pliny expressed a thoroughly Roman conservative position: as the cities' financial solvency depended on the councilmen's purses, it was necessary to have more councilmen on the local city councils. According to Pliny, the best way to achieve this was to lower the minimum age for holding a seat on the council, making it possible for more sons of the established oligarchical families to join and thus contribute to civic spending; this was seen as preferable to enrolling non-noble wealthy upstarts.^[85]

Such an increase in the number of council members was granted to Dio's city of Prusa, to the dismay of existing councilmen who felt their status lowered.^[86] A similar situation existed in Claudiopolis, where a public bath was built with the proceeds from the entrance fees paid by "supernumerary" members of the Council, enrolled with Trajan's permission.^[87] Also, according to the Digest, it was decreed by Trajan that when a city magistrate promised to achieve a particular public building, it was incumbent on his heirs to complete the building.^[88]

Trajan ingratiated himself with the Greek intellectual elite by recalling to Rome many (including Dio) who had been exiled by Domitian,^[89] and by returning (in a process begun by Nerva) a great deal of private property that Domitian had confiscated. He also had good dealings with Plutarch, who, as a notable of Delphi, seems to have been favored by the decisions taken on behalf of his home-place by one of Trajan's legates, who had arbitrated a boundary dispute between Delphi and its neighboring cities.^[90] However, it was clear to Trajan that Greek intellectuals and notables were to be regarded as tools for local administration, and not be allowed to fancy themselves in a privileged position.^[91] As Pliny said in one of his letters at the time, it was official policy that Greek civic elites be treated according to their status as notionally free but not put on an equal footing with their Roman rulers.^[92] When the city of Apamea complained of an audit of its accounts by Pliny, alleging its "free" status as a Roman colony, Trajan replied by writing that it was by his own wish that such inspections had been ordered. Concern about independent local political activity is seen in Trajan's decision to forbid Nicomedia from having a corps of firemen ("If people assemble for a common purpose ... they soon turn it into a political society", Trajan wrote to Pliny) as well as in his and Pliny's fears about excessive civic generosities by local notables such as distribution of money or gifts.^[93] For the same reason, judging from Pliny's letters it can also be assumed that Trajan and his aides were as much bored as they were alarmed by the claims of Dio and other Greek notables to political influence based on what they saw as their "special connection" to their Roman overlords.^[94] A revealing case-history, told by Pliny, tells of Dio of Prusa placing a statue of Trajan in a building complex where Dio's wife and son were buried - therefore incurring a charge of treason for placing the Emperor's statue near a grave. Trajan, however, dropped the charge.^[95]

Nevertheless, while the office of corrector was intended as a tool to curb any hint of independent political activity among local notables in the Greek cities,^[96] the correctores themselves were all men of the highest social standing entrusted with an exceptional commission. The post seems to have been conceived partly as a reward for senators who had chosen to make a career solely on the Emperor's behalf. Therefore, in reality the post was conceived as a means for "taming" both Greek notables and Roman senators.^[97] It must be added that, although Trajan was wary of the civic oligarchies in the Greek cities, he also admitted into the Senate a number of prominent Eastern notables already slated for promotion during Domitian's reign by reserving for them one of the twenty posts open each year for minor magistrates (the vigintiviri).^[98] Such must be the case of the Galatian notable and "leading member of the Greek community" (according to one inscription) Gaius Julius Severus, who was a descendant of several Hellenistic dynasts and client kings.^[99] Severus was the grandfather of the prominent general Gaius Julius Quadratus Bassus, consul in 105.^[100] Other prominent Eastern senators included Gaius Julius Alexander Berenicianus, a descendant of Herod the Great, suffect consul in 116.^[101] Trajan created at least fourteen new senators from the Greek-speaking half of the Empire, an unprecedented recruitment number that opens to question the issue of the "traditionally Roman" character of his reign, as well as the "Hellenism" of his successor Hadrian.^[102] But then Trajan's new Eastern senators were mostly very powerful and very wealthy men with more than local influence^[103] and much interconnected by marriage, so that many of them were not altogether "new" to the Senate.^[104] On the local level, among the lower section of the Eastern propertied,^[105] the alienation of most Greek notables and intellectuals towards Roman rule, and the fact that the Romans were seen by most such Greek notables as aliens, persisted well after Trajan's reign.^[106] One of Trajan's senatorial creations from the East, the Athenian Gaius Julius Antiochus Epiphanes Philopappos, a member of the Royal House of Commagene, left behind him a funeral monument on the Mouseion Hill that was later disparagingly described by Pausanias as "a monument built to a Syrian man".^[107]

Trajan is known particularly for his conquests in the Near East, but initially for the two wars against Dacia – the reduction to client kingdom (101–102), followed by actual incorporation into the Empire of the trans-Danube border group of Dacia – an area that had troubled Roman thought for over a decade with the unstable peace negotiated by Domitian's ministers with the powerful Dacian king Decebalus.^[108] According to the provisions of this treaty, Decebalus was acknowledged as rex amicus, that is, client king; nevertheless, in exchange for accepting client status, he received a generous stipend from Rome, as well as being supplied with technical experts.^[109] The treaty seems to have allowed Roman troops the right of passage through the Dacian kingdom in order to attack the Marcomanni, Quadi and Sarmatians. However, senatorial opinion never forgave Domitian for paying what was seen as "tribute" to a Barbarian king.^[110] In addition, unlike the Germanic tribes, the Dacian kingdom was an organized state capable of developing alliances of its own,^[111] thus making it a strategic threat and giving Trajan a strong motive to attack it.^[112]

In May of 101, Trajan launched his first campaign into the Dacian kingdom,^[113] crossing to the northern bank of the Danube and defeating the Dacian army at Tapae (see Second Battle of Tapae), near the Iron Gates of Transylvania. It was not a decisive victory, however.^[114] Trajan's troops were mauled in the encounter, and he put off further campaigning for the year in order to regroup and reinforce his army.^[115]

The following winter, King Decebalus took the initiative by launching a counter-attack across the Danube further downstream, supported by Sarmatian cavalry,^[116] forcing Trajan to come to the aid of the troops in his rearguard. The Dacians and their allies were repulsed after two battles in Moesia, at Nicopolis ad Istrum and Adamclisi.^{[[117]](http://www.sarmizegetusa.org/doc/Glodariu%20I.%20-%20La%20zone%20de%20Sarmizegetusa%20et%20les%20guerres%20de%20Trajan(Studia%20Antiqua%20et%20Archaeologica,)} Trajan's army then advanced further into Dacian territory, and, a year later, forced Decebalus to submit. He had to renounce claim to some regions of his kingdom, return all Roman runaways (most of them technical experts), and surrender all his war machines.^[118] Trajan returned to Rome in triumph and was granted the title Dacicus.^[119]

The peace of 102 had returned Decebalus to the condition of more or less harmless client king; however, he soon began to rearm, to again harbor Roman runaways, and to pressure his Western neighbors, the Iazyges Sarmatians, into allying themselves with him. By trying to develop an anti-Roman bloc, Decebalus eventually left Trajan without the alternative of treating Dacia as a protectorate, rather than an outright conquest.^[120] In 104 Decebalus devised a failed attempt on Trajan's life by means of some Roman deserters, and held prisoner Trajan's legate Longinus, who eventually poisoned himself while in custody. Finally, in 105, Decebalus undertook an invasion of Roman-occupied territory north of the Danube.^[121][122]

Prior to the campaign, Trajan had raised two entirely new legions: II Traiana – which, however, may have been posted in the East, at the Syrian port of Laodicea – and XXX Ulpia Victrix, which was posted to Brigetio, in Pannonia.^[121][123] By 105, the concentration of Roman troops assembled in the middle and lower Danube amounted to fourteen legions (up from nine in 101) – about half of the entire Roman army.^[124] Even after the Dacian wars, the Danube frontier would permanently replace the Rhine as the main military axis of the Roman Empire.^[125] Including auxiliaries, the number of Roman troops engaged on both campaigns was between 150,000 and 175,000, while Decebalus could dispose of up to 200,000.^[114]

Following the design of Apollodorus of Damascus, Trajan ordered the building of a massive bridge over the Danube, over which the Roman army was able to cross the river swiftly and in numbers, as well as to send in reinforcements, even in winter when the river was not frozen enough to bear the passage of a party of soldiers.^[126] Trajan also reformed the infrastructure of the Iron Gates region of the Danube. He commissioned either the creation or enlargement of the road along the Iron Gates, carved into the side of the gorge.^[127] Additionally, Trajan commissioned a canal to be built around the rapids of the Iron Gates. Evidence of this comes from a marble slab discovered near Caput Bovis, the site of a Roman fort. The slab, dated to the year 101, commemorates the building of at least one canal that went from the Kasajna tributary to at least Ducis Pratum, whose embankments were still visible until recently. However, the placement of the slab at Caput Bovis suggests that the canal extended to this point or that there was a second canal downriver of the Kasajna-Ducis Pratum one.^[128]

These costly projects completed,^[129] in 105 Trajan again took to the field. In a fierce campaign which seems to have consisted mostly of static warfare, the Dacians, devoid of maneuvering room, kept to their network of fortresses, which the Romans sought systematically to storm^[130] (see also Second Dacian War). The Romans gradually tightened their grip around Decebalus' stronghold in Sarmizegetusa Regia,^[125] which they finally took and destroyed. Decebalus fled, but, when cornered by Roman cavalry, committed suicide. His severed head, brought to Trajan by the cavalryman Tiberius Claudius Maximus,^[131] was later exhibited in Rome on the steps leading up to the Capitol and thrown on the Gemonian stairs.^[132]

Trajan built a new city, Colonia Ulpia Traiana Augusta Dacica Sarmizegetusa, on another site (north of the hill citadel holding the previous Dacian capital),^[133] although bearing the same full name, Sarmizegetusa. This capital city was conceived as a purely civilian administrative center and was provided the usual Romanized administrative apparatus (decurions, aediles, etc.).^[134] Urban life in Roman Dacia seems to have been restricted to Roman colonists, mostly military veterans;^[135] there is no extant evidence for the existence in the province of peregrine cities. Native Dacians continued to live in scattered rural settlements, according to their own ways.^[136] In another arrangement with no parallels in any other Roman province, the existing quasi-urban Dacian settlements disappeared after the Roman conquest.^[137] A number of unorganized urban settlements (vici) developed around military encampments in Dacia proper - the most important being Apulum - but were only acknowledged as cities proper well after Trajan's reign.^[138]

The main regional effort of urbanization was concentrated by Trajan at the rearguard, in Moesia, where he created the new cities of Nicopolis ad Istrum and Marcianopolis. A vicus was also created around the Tropaeum Traianum.^[139] The garrison city of Oescus received the status of Roman colony after its legionary garrison was redeployed.^[139] The fact that these former Danubian outposts had ceased to be frontier bases and were now in the deep rear acted as an inducement to their urbanization and development.^[140]

Not all of Dacia was permanently occupied. What was permanently included in the province, after the post-Trajanic evacuation of some land across the lower Danube,^[141] were the lands extending from the Danube to the inner arch of the Carpathian Mountains, including Transylvania, the Metaliferi Mountains and Oltenia. The Roman province eventually took the form of an "excrescence" North of the Danube, with ill-defined limits, stretching from the Danube northwards to the Carpathians,^[125] and was intended perhaps as a basis for further expansion in Eastern Europe – which the Romans conceived to be much more "flattened", and closer to the ocean, than it actually was.^[142] Defense of the province was entrusted to a single legion, the XIII Gemina, stationed at Apulum, which functioned as an advanced guard that could, in case of need, strike either west or east at the Sarmatians living at the borders.^[140] Therefore, the indefensible character of the province did not appear to be a problem for Trajan, as the province was conceived more as a sally-base for further attacks.^[143] Even in the absence of further Roman expansion, the value of the province depended on Roman overall strength: while Rome was strong, the Dacian salient was an instrument of military and diplomatic control over the Danubian lands; when Rome was weak, as during the Crisis of the Third Century, the province became a liability and was eventually abandoned.^[144]

Trajan resettled Dacia with Romans and annexed it as a province of the Roman Empire. Aside from their enormous booty (over half a million slaves, according to John Lydus),^[145] Trajan's Dacian campaigns benefited the Empire's finances through the acquisition of Dacia's gold mines, managed by an imperial procurator of equestrian rank (procurator aurariarum).^[146] On the other hand, commercial agricultural exploitation on the villa model, based on the centralized management of a huge landed estate by a single owner (fundus) was poorly developed.^[147] Therefore, use of slave labor in the province itself seems to have been relatively undeveloped, and epigraphic evidence points to work in the gold mines being conducted by means of labor contracts (locatio conductio rei) and seasonal wage-earning.^[148] The victory was commemorated by the construction both of the 102 cenotaph generally known as the Tropaeum Traiani in Moesia, as well of the much later (113) Trajan's Column in Rome, the latter depicting in stone carved bas-reliefs the Dacian Wars' most important moments.^[149]

In 106, Rabbel II Soter, one of Rome's client kings, died. This event might have prompted the annexation of the Nabataean kingdom, but the manner and the formal reasons for the annexation are unclear. Some epigraphic evidence suggests a military operation, with forces from Syria and Egypt. What is known is that by 107, Roman legions were stationed in the area around Petra and Bostra, as is shown by a papyrus found in Egypt. The furthest south the Romans occupied (or, better, garrisoned, adopting a policy of having garrisons at key points in the desert)^[150] was Hegra, over 300 kilometres (190 mi) south-west of Petra.^[151] The empire gained what became the province of Arabia Petraea (modern southern Jordan and north west Saudi Arabia).^[152] As Nabataea was the last client kingdom in Asia west of the Euphrates, the annexation meant that the entire Roman East had been provincialized, completing a trend towards direct rule that had begun under the Flavians.^[150]

For the next seven years, Trajan ruled as a civilian emperor, to the same acclaim as before. It was during this time that he corresponded with Pliny the Younger on the subject of how to deal with the Christians of Pontus, telling Pliny to continue to persecute Christians but not to accept anonymous denunciations in the interests of justice as well as of "the spirit of the age". Non-citizens who admitted to being Christians and refused to recant, however, were to be executed "for obstinacy". Citizens were sent to Rome for trial.^[153]

Trajan built several new buildings, monuments and roads in Italia and his native Hispania. His magnificent complex in Rome raised to commemorate his victories in Dacia (and largely financed from that campaign's loot) – consisting of a forum, Trajan's Column, and Trajan's Market, still stands in Rome today. He was also a prolific builder of triumphal arches, many of which survive, and a builder of roads such as the Via Traiana - the extension of the Via Appia from Beneventum to Brundisium^[154] - and Via Traiana Nova, a mostly military road between Damascus and Aila, whose building was connected to the founding of the province of Arabia (see see annexation of Nabataea) .^[155]

One of Trajan's notable acts during this period was the hosting of a three-month gladiatorial festival in the great Colosseum in Rome (the precise date is unknown). Combining chariot racing, beast fights and close-quarters gladiatorial bloodshed, this gory spectacle reputedly left 11,000 dead (mostly slaves and criminals, not to mention the thousands of ferocious beasts killed alongside them) and attracted a total of five million spectators over the course of the festival. The care bestowed by Trajan on the managing of such public spectacles led the orator Fronto to state approvingly that Trajan had paid equal attention to entertainments as well as to serious issues. Fronto concluded that "neglect of serious matters can cause greater damage, but neglect of amusements greater discontent".^[156] As Fronto added, amusements were a means to assure the general acquiescence of the populace, while the more "serious" issue of the corn dole aimed ultimately only at individuals.^[157]

In 107 Trajan devalued the Roman currency. He decreased the silver purity of the denarius from 93.5% to 89% – the actual silver weight dropping from 3.04 grams to 2.88 grams.^[158] This devaluation, coupled with the massive amount of gold and silver carried off after Trajan's Dacian Wars, allowed the emperor to mint a larger quantity of denarii than his predecessors. Also, Trajan withdrew from circulation silver denarii minted before the previous devaluation achieved by Nero, something that allows for thinking that Trajan's devaluation had to do with political ends, such as allowing for increased civil and military spending.^[159]

Another important act was his formalisation of the alimenta, a welfare program that helped orphans and poor children throughout Italy. It provided general funds, as well as food and subsidized education. The program was supported initially out of Dacian War booty, and then later by a combination of estate taxes and philanthropy.^[160] In general terms, the scheme functioned by means of mortgages on Italian farms (fundi), through which registered landowners received a lump sum from the imperial treasure, being in return expected to pay yearly a given proportion of the loan to the maintenance of an alimentary fund.^[161]

Although the system is well documented in literary sources and contemporary epigraphy, its precise aims are controversial and have generated considerable dispute among modern scholars, especially about its actual aims and scope as a piece of welfare policy. It is usually assumed that the program was intended to bolster citizen numbers in Italy, following the provisions of Augustus' moral legislation (Lex Julia) favoring procreation on moral grounds – something openly acknowledged by Pliny.^[162] Nevertheless, this reproductive aim was anachronistic, based as it was on a view of the Roman Empire as centered on Rome and Italy, with a purely Italian manpower base, both increasingly no longer the case.^[163] This outdated stance was confirmed by Pliny when he wrote that the recipients of the alimenta were supposed to people "the barracks and the tribes" as future soldiers and electors – two roles ill-fitted to the contemporary reality of an empire stretching across the entire Mediterranean and ruled by an autocrat.^[164] The fact that the scheme was restricted to Italy suggests that it might have been conceived as a form of political privilege accorded to the original heartland of the empire.^[165] According to the French historian Paul Petit, the alimenta should be seen as part of a set of measures aimed towards the economic recovery of Italy.^[166] Finley thinks that the scheme's chief aim was the artificial bolstering of the political weight of Italy, as seen, for example, in the stricture – heartily praised by Pliny – laid down by Trajan that ordered all senators, even when from the provinces, to have at least a third of their landed estates in Italian territory, as it was "unseemly [...] that [they] should treat Rome and Italy not as their native land, but as a mere inn or lodging house".^[167]

"Interesting and unique" as the scheme was, it remained small.^[168] The fact that it was subsidized by means of interest payments on loans made by landowners – mostly large ones, assumed to be more reliable debtors^[169] – actually benefited a very low percentage of potential welfare recipients (Paul Veyne has assumed that, in the city of Veleia, only one child out of ten was an actual beneficiary) – thus the idea, put forth by Moses I. Finley, that the grandiose aims amounted to at most a form of random charity, an additional imperial benevolence.^[170] Reliance solely on loans to great landowners (in Veleia, only some 17 square kilometers were mortgaged)^[171] restricted funding sources even further. It seems that the mortgage scheme was simply a way of making local notables participate, albeit in a lesser role, in imperial benevolence.^[172] It is possible that the scheme was, to some extent, a forced loan, something that tied unwilling landowners to the imperial treasure in order to make them supply some funds to civic expenses.^[173] The same notion of exploiting private – and supposedly more efficient – management of a landed estate as a means to obtain public revenue was also employed by other similar and lesser schemes. The senator Pliny had endowed his city of Comum a perpetual right to an annual charge (vectigal) of thirty thousand sestertii on one of his estates in perpetuity even after his death (Pliny's heirs or any subsequent purchaser of the estate being liable), with the rent thus obtained contributing to the maintenance of Pliny's semi-private charitable foundation.^[174] With such a scheme, Pliny probably hoped to engender enthusiasm among fellow landowners for such philanthropic ventures. Trajan did likewise, but since "willingness is a slippery commodity", Finley suspects that, in order to ensure Italian landowners' acceptance of the burden of borrowing from the alimenta fund, some "moral" pressure was exerted.^[175]

In short, the scheme was so limited in scope that it could not have fulfilled a coherent economic or demographic purpose – it was the usual Ancient charity, directed, not towards the poor, but to the community (in this case, the Italian cities) as a whole.^[176] The fact that the alimenta was begun during and after the Dacian Wars and twice came on the heels of a distribution of money to the population of Rome (congiaria) following Dacian triumphs, points towards a purely charitable motive.^[177] The fact that the alimenta was restricted to Italy highlights the ideology behind it: to reaffirm the notion of the Roman Empire as an Italian overlordship.^[163] Given its limited scope, the plan was, nevertheless, very successful in that it lasted for a century and a half: the last known official in charge of it is attested during the reign of Aurelian.^[178]

In 113, Trajan embarked on his last campaign, provoked by Parthia's decision to put an unacceptable king on the throne of Armenia, a kingdom over which the two great empires had shared hegemony since the time of Nero some fifty years earlier. It's noteworthy, however, that Trajan, already in Syria early in 113, consistently refused to accept diplomatic approaches from the Parthians in order to settle the Armenian imbroglio peacefully.^[180]

As the surviving literary accounts of Trajan's Parthian War are fragmentary and scattered,^[181] it is difficult to assign them a proper context, something that has led to a long-running controversy about its precise happenings and ultimate aims. Many modern historians consider that Trajan's decision to wage war against Parthia might have had economic motives: after Trajan's annexation of Arabia, he built a new road, Via Traiana Nova, that went from Bostra to Aila on the Red Sea.^[182] That meant that Charax on the Persian Gulf was the sole remaining western terminus of the Indian trade route outside direct Roman control,^[183] and such control was important in order to lower import prices and to limit the supposed drain of precious metals created by the deficit in Roman trade with the Far East.^[184]

That Charax traded with the Roman Empire, there can be no doubt, as its actual connections with merchants from Palmyra during the period are well documented in a contemporary Palmyrene epigraph, which tells of various Palmyrene citizens honoured for holding office in Charax.^[185] Also, Charax's rulers domains at the time possibly included the Bahrain islands (where a Palmyrene citizen held office, shortly after Trajan's death, as satrap^[186] – but then, the appointment was made by a Parthian king of Charax^[187]) something which offered the possibility of extending Roman hegemony into the Persian Gulf itself.^[188] The rationale behind Trajan's campaign, in this case, was one of breaking down a system of Far Eastern trade through small Semitic ("Arab") cities under Parthia's control and to put it under Roman control instead.^[189]

In his Dacian conquests, Trajan had already resorted to Syrian auxiliary units, whose veterans, along with Syrian traders, had an important role in the subsequent colonization of Dacia.^[190] He had recruited Palmyrene units into his army, including a camel unit,^[191] therefore apparently procuring Palmyrene support to his ultimate goal of annexing Charax. It has even been ventured that, when earlier in his campaign Trajan annexed Armenia, he was bound to annex the whole of Mesopotamia lest the Parthians interrupt the flux of trade from the Persian Gulf and/or foment trouble at the Roman frontier on the Danube.^[192]

Other historians reject these motives, as the supposed Parthian "control" over the maritime Far Eastern trade route was, at best, conjectural and based on a selective reading of Chinese sources – trade by land through Parthia seems to have been unhampered by Parthian authorities and left solely to the devices of private enterprise.^[193] Commercial activity in second century Mesopotamia seems to have been a general phenomenon, shared by many peoples within and without the Roman Empire, with no sign of a concerted Imperial policy towards it.^[194] As in the case of the alimenta, scholars like Moses Finley and Paul Veyne have considered the whole idea of a foreign trade "policy" behind Trajan's war anachronistic: according to them, the sole Roman concern with the Far Eastern luxuries trade – besides collecting toll taxes and customs^[195] – was moral and involved frowning upon the "softness" of luxuries, but no economic policy.^[196][197] In the absence of conclusive evidence, trade between Rome and India might have been far more balanced, in terms of quantities of precious metals exchanged: one of our sources for the notion of the Roman gold drain – Pliny's the Younger's uncle Pliny the Elder – had earlier described the Gangetic Plains as one of the gold sources for the Roman Empire.^[198] Accordingly, in his controversial book on the Ancient economy, Finley considers Trajan's "badly miscalculated and expensive assault on Parthia" to be an example of the many Roman "commercial wars" that had in common the fact of existing only in the books of modern historians.^[194]

The alternative view is to see the campaign as triggered by the lure of territorial annexation and prestige,^[194] the sole motive ascribed by Cassius Dio.^[199] As far as territorial conquest involved tax-collecting,^[200] especially of the 25% tax levied on all goods entering the Roman Empire, the tetarte, one can say that Trajan's Parthian War had an "economic" motive.^[201] Also, there was the propaganda value of an Eastern conquest that would emulate, in Roman fashion, those of Alexander the Great.^[202] The fact that emissaries from the Kushan Empire might have attended to the commemorative ceremonies for the Dacian War may have kindled in some Greco-Roman intellectuals like Plutarch – who wrote about only 70,000 Roman soldiers being necessary to a conquest of India – as well as in Trajan's closer associates, speculative dreams about the booty to be obtained by reproducing Macedonian Eastern conquests.^[203] There could also be Trajan's idea to use an ambitious blueprint of conquests as a way to emphasize quasi-divine status, such as with his cultivated association, in coins and monuments, to Hercules.^[204] Also, it is possible that the attachment of Trajan to an expansionist policy was supported by a powerful circle of conservative senators from Hispania committed to a policy of imperial expansion, first among them being the all-powerful Licinius Sura.^[205] Alternatively, one can explain the campaign by the fact that, for the Romans, their empire was in principle unlimited, and that Trajan only took advantage of an opportunity to make idea and reality coincide.^[206]

Finally, there are other modern historians who think that Trajan's original aims were purely military and quite modest: to assure a more defensible Eastern frontier for the Roman Empire, crossing Northern Mesopotamia along the course of the Khabur River in order to offer cover to a Roman Armenia.^[207] This interpretation is backed by the fact that all subsequent Roman wars against Parthia would aim at establishing a Roman presence deep into Parthia itself.^[208]

The campaign was carefully planned in advance: ten legions were concentrated in the Eastern theater; since 111, the correspondence of Pliny the Younger witnesses to the fact that provincial authorities in Bithynia had to organize supplies for passing troops, and local city councils and their individual members had to shoulder part of the increased expenses by supplying troops themselves.^[209] The intended campaign, therefore, was immensely costly from its very beginning.^[210]

Trajan marched first on Armenia, deposed the Parthian-appointed king, Parthamasiris (who was afterwards murdered while kept in the custody of Roman troops in an unclear incident, later described by Fronto as a breach of Roman good faith^[211]), and annexed it to the Roman Empire as a province, receiving in passing the acknowledgement of Roman hegemony by various tribes in the Caucasus and on the Eastern coast of the Black Sea – a process that kept him busy until the end of 114.^[212] At the same time, a Roman column under the legate Lusius Quietus – an outstanding cavalry general^[213] who had signaled himself during the Dacian Wars by commanding a unit from his native Mauretania^[214] – crossed the Araxes river from Armenia into Media Atropatene and the land of the Mardians (present-day Ghilan).^[215] It is possible that Quietus' campaign had as its goal the extending of the newer, more defensible Roman border eastwards towards the Caspian Sea and northwards to the foothills of the Caucasus.^[216] This newer, more "rational" frontier, depended, however, on an increased, permanent Roman presence east of the Euphrates.^[217]

The chronology of subsequent events is uncertain, but it is generally believed that early in 115 Trajan launched a Mesopotamian campaign, marching down towards the Taurus mountains in order to consolidate territory between the Tigris and Euphrates rivers. He placed permanent garrisons along the way to secure the territory.^[218] While Trajan moved from west to east, Lusius Quietus moved with his army from the Caspian Sea towards the west, both armies performing a successful pincer movement,^[219] whose apparent result was to establish a Roman presence into the Parthian Empire proper, with Trajan taking the northern Mesopotamian cities of Nisibis and Batnae and organizing a province of Mesopotamia, including the Kingdom of Osrhoene – where King Abgaros VII submitted to Trajan publicly^[220] – as a Roman protectorate.^[221] This process seems to have been completed at the beginning of 116, when coins were issued announcing that Armenia and Mesopotamia had been put under the authority of the Roman people.^[222] The area between the Khabur River and the mountains around Singara seems to have been considered as the new frontier, and as such received a road surrounded by fortresses.^[223]

After wintering in Antioch during 115/116  – and, according to literary sources, barely escaping from a violent earthquake that claimed the life of one of the consuls, M. Pedo Virgilianus^[224][225] – Trajan again took to the field in 116, with a view to the conquest of the whole of Mesopotamia, an overambitious goal that eventually backfired on the results of his entire campaign. According to some modern historians, the aim of the campaign of 116 was to achieve a "preemptive demonstration" aiming not toward the conquest of Parthia, but for tighter Roman control over the Eastern trade route. However, the overall scarcity of manpower for the Roman military establishment meant that the campaign was doomed from the start.^[226] It is noteworthy that no new legions were raised by Trajan before the Parthian campaign, maybe because the sources of new citizen recruits were already over-exploited.^[227]

As far as the sources allow a description of this campaign, it seems that one Roman division crossed the Tigris into Adiabene, sweeping south and capturing Adenystrae; a second followed the river south, capturing Babylon; Trajan himself sailed down the Euphrates from Dura-Europos – where a triumphal arch was erected in his honour – through Ozogardana, where he erected a "tribunal" still to be seen at the time of Julian the Apostate's campaigns in the same area. Having come to the narrow strip of land between the Euphrates and the Tigris, he then dragged his fleet overland into the Tigris, capturing Seleucia and finally the Parthian capital of Ctesiphon.^[228][229]

He continued southward to the Persian Gulf, when, after escaping with his fleet a tidal bore on the Tigris,^[230] he received the submission of Athambelus, the ruler of Charax. He declared Babylon a new province of the Empire and had his statue erected on the shore of the Persian Gulf,^[231] after which he sent the Senate a laurelled letter declaring the war to be at a close and bemoaning that he was too old to go on any further and repeat the conquests of Alexander the Great.^[221] Since Charax was a de facto independent kingdom whose connections to Palmyra were described above, Trajan's bid for the Persian Gulf may have coincided with Palmyrene interests in the region.^[232] Another hypothesis is that the rulers of Charax had expansionist designs on Parthian Babylon, giving them a rationale for alliance with Trajan.^[233] The Parthian summer capital of Susa was apparently also occupied by the Romans.^[234]

According to late literary sources (not backed by numismatic or inscriptional evidence) a province of Assyria was also proclaimed,^[235] apparently covering the territory of Adiabene.^[236] Some measures seem to have been considered regarding the fiscal administration of Indian trade – or simply about the payment of customs (portoria) on goods traded on the Euphrates and Tigris.^[237][232] It is possible that it was this "streamlining" of the administration of the newly conquered lands according to the standard pattern of Roman provincial administration in tax collecting, requisitions and the handling of local potentates' prerogatives, that triggered later resistance against Trajan.^[238]

According to some modern historians, Trajan might have busied himself during his stay on the Persian Gulf with ordering raids on the Parthian coasts,^[239] as well as probing into extending Roman suzerainty over the mountaineer tribes holding the passes across the Zagros Mountains into the Iranian Plateau eastward, as well as establishing some sort of direct contact between Rome and the Kushan Empire.^[240] No attempt was made to expand into the Iranian Plateau itself, where the Roman army, with its relative weakness in cavalry, would have been at a disadvantage.^[241]

Trajan left the Persian Gulf for Babylon – where he intended to offer sacrifice to Alexander in the house where he had died in 323 BC^[242] –  But Sanatruces, a sudden nephew of the Parthian king Osroes I who had retained a cavalry force, possibly strengthened by the addition of Saka archers,^[243] imperiled Roman positions in Mesopotamia and Armenia. Trajan sought to deal with this by forsaking direct Roman rule in Parthia proper, at least partially.^[244]

Trajan sent two armies towards Northern Mesopotamia: the first, under Lusius Quietus, recovered Nisibis and Edessa from the rebels, probably having King Abgarus deposed and killed in the process,^[244] with Quietus probably earning the right to receive the honors of a senator of praetorian rank (adlectus inter praetorios).^[245] The second army, however, under Appius Maximus Santra (probably a governor of Macedonia) was defeated and Santra killed.^[246] Later in 116, Trajan, with the assistance of Quietus and two other legates, Marcus Erucius Clarus and Tiberius Julius Alexander Julianus,^[247][248] defeated a Parthian army in a battle where Sanatruces was killed (possibly with the assistance of Osroes' son and Sanatruces' cousin, Parthamaspates, whom Trajan wooed successfully).^[249] After re-taking and burning Seleucia, Trajan then formally deposed the Osroes, putting Parthamaspates on the throne as client ruler. This event was commemorated in a coin so as to be presented as the reduction of Parthia to client kingdom status: REX PARTHIS DATUS, "a king is given to the Parthians".^[250] That done, Trajan retreated north in order to retain what he could of the new provinces of Armenia – where he had already accepted an armistice in exchange for surrendering part of the territory to Sanatruces' son Vologeses^[251] – and Mesopotamia. It was at this point that Trajan's health started to fail him. The fortress city of Hatra, on the Tigris in his rear, continued to hold out against repeated Roman assaults. He was personally present at the siege, and it is possible that he suffered a heat stroke while in the blazing heat.^[244]

Shortly afterwards, the Jews inside the Eastern Roman Empire, in Egypt, Cyprus and Cyrene – this last province being probably the original trouble hotspot – rose up in what probably was an outburst of religious rebellion against the local pagans, this widespread rebellion being afterwards named the Kitos War.^[252] Another rebellion flared up among the Jewish communities of Northern Mesopotamia, probably part of a general reaction against Roman occupation.^[253] Trajan was forced to withdraw his army in order to put down the revolts. He saw this withdrawal as simply a temporary setback, but he was destined never to command an army in the field again, turning his Eastern armies over to Lusius Quietus, who meanwhile (early 117) had been made governor of Judaea and might have had to deal earlier with some kind of Jewish unrest in the province.^[254] Quietus discharged his commissions successfully, so much that the war was afterward named after him – Kitus being a corruption of Quietus.^[255] Whether or not the Kitos War theater included Judea proper, or only the Jewish Eastern diaspora, remains doubtful in the absence of clear epigraphic and archaeological evidence. What is certain is that there was an increased Roman military presence in Judea at the time.^[256]

Quietus was promised a consulate^[257] in the following year (118) for his victories, but he was killed before this could occur, during the bloody purge that opened Hadrian's reign, in which Quietus and three other former consuls were sentenced to death after being tried on a vague charge of conspiracy by the (secret) court of the Praetorian Prefect Attianus.^[258] It has been theorized that Quietus and his colleagues were executed on Hadrian's direct orders, for fear of their popular standing with the army and their close connections to Trajan.^[251][259]

In contrast, the next prominent Roman figure in charge of the repression of the Jewish revolt, the equestrian Quintus Marcius Turbo, who had dealt with the rebel leader from Cyrene, Loukuas,^[260] retained Hadrian's trust, eventually becoming his Praetorian Prefect. As all four consulars were senators of the highest standing and as such generally regarded as able to take imperial power (capaces imperii), Hadrian seems to have decided on a preemptive strike against these prospective rivals.^[261]

Early in 117, Trajan grew ill and set out to sail back to Italy. His health declined throughout the spring and summer of 117, something publicly acknowledged by the fact that a bronze bust displayed at the time in the public baths of Ancyra showed him clearly aged and emaciated.^[262] After reaching Selinus (modern Gazipaşa) in Cilicia, which was afterwards called Trajanopolis, he suddenly died from edema on August 8. Some say that Trajan had adopted Hadrian as his successor, but others that it was his wife Pompeia Plotina who assured the succession to Hadrian by keeping his death secret and afterwards hiring someone to impersonate Trajan by speaking with a tired voice behind a curtain, well after Trajan had died. Dio, who tells this narrative, offers his father – the then governor of Cilicia Apronianus – as a source, and therefore his narrative is possibly grounded on contemporary rumor. It may also originate in Roman displeasure at an empress meddling in political affairs.^[263]

Hadrian held an ambiguous position during Trajan's reign. After commanding Legio I Minervia during the Dacian Wars, he had been relieved from front-line duties at the decisive stage of the Second Dacian War, being sent to govern the newly created province of Pannonia Inferior. He had pursued a senatorial career without particular distinction and had not been officially adopted by Trajan (although he received from him decorations and other marks of distinction that made him hope for the succession).^[264][265] He received no post after his 108 consulate,^[266] and no further honours other than being made Archon eponymos for Athens in 111/112.^[267] He probably did not take part in the Parthian War. Literary sources relate that Trajan had considered others, such as the jurist Lucius Neratius Priscus, as heir.^[268] However, Hadrian, who was eventually entrusted with the governorship of Syria at the time of Trajan's death, was Trajan's cousin and was married to Trajan's grandniece,^[269] which all made him as good as heir designate.^[270] In addition Hadrian was born in Hispania and seems to have been well connected with the powerful group of Spanish senators influential at Trajan's court through his ties to Plotina and the Prefect Attianus.^[271] The fact that during Hadrian's reign he did not pursue Trajan's senatorial policy may account for the "crass hostility" shown him by literary sources.^[272]

Aware that the Parthian campaign was an enormous setback, and that it revealed that the Roman Empire had no means for an ambitious program of conquests,^[120] Hadrian's first act as emperor was to abandon – outwardly out of his own free will^[273][274] – the distant and indefensible Mesopotamia and to restore Armenia, as well as Osrhoene, to the Parthian hegemony under Roman suzerainty.^[237] However, all the other territories conquered by Trajan were retained. Roman friendship ties with Charax (also known by the name of Mesene) were also retained (although it is debated whether this had to do more with trade concessions than with common Roman policy of exploiting dissensions amid the Empire's neighbors).^[275][276] Trajan's ashes were laid to rest underneath Trajan's column, the monument commemorating his success.^[277]

Trajan was a prolific builder in Rome and the provinces, and many of his buildings were erected by the gifted architect Apollodorus of Damascus. Notable structures include the Baths of Trajan, Trajan's Forum, Trajan's Column, Trajan's Bridge, Alcántara Bridge, Porto di Traiano of Portus, the road and canal around the Iron Gates (see conquest of Dacia), and possibly the Alconétar Bridge. Some historians also attribute the construction of the Babylon fortress in Egypt to Trajan;^[278] the remains of the fort is what is now known as the Church of Mar Girgis and its surrounding buildings. In order to build his forum and the adjacent brick market that also held his name Trajan had vast areas of the surrounding Capitoline and Quirinal hills leveled.^[279][280]

Ancient sources on Trajan's personality and accomplishments are unanimously positive. Pliny the Younger, for example, celebrates Trajan in his panegyric as a wise and just emperor and a moral man. Cassius Dio added that he always remained dignified and fair.^[281] A Third Century Emperor, Decius, even received from the Senate the name Trajan as a decoration.^[282] After the setbacks of the third century, Trajan, together with Augustus, became in the Later Roman Empire the paragon of the most positive traits of the Imperial order.^[283]

Some theologians such as Thomas Aquinas discussed Trajan as an example of a virtuous pagan. In the Divine Comedy, Dante, following this legend, sees the spirit of Trajan in the Heaven of Jupiter with other historical and mythological persons noted for their justice. Also, a mural of Trajan stopping to provide justice for a poor widow is present in the first terrace of Purgatory as a lesson to those who are purged for being proud.^[284]

In the 18th-century King Charles III of Spain commissioned Anton Raphael Mengs to paint The Triumph of Trajan on the ceiling of the banquet hall of the Royal Palace of Madrid – considered among the best works of this artist.^[286]

It was only during the Enlightenment that this legacy began to be contested, when Edward Gibbon expressed doubts about the militarized character of Trajan's reign in contrast to the "moderate" practices of his immediate successors.^[287] Mommsen adopted a divided stance towards Trajan, at some point of his posthumously published lectures even speaking about his "vainglory" (Scheinglorie).^[288] Mommsen also speaks of Trajan's "insatiable, unlimited lust for conquest".^[289] Although Mommsen had no liking for Trajan's successor Hadrian – "a repellent manner, and a venomous, envious and malicious nature" – he admitted that Hadrian, in renouncing Trajan's conquests, was "doing what the situation clearly required".^[290]

It was exactly this military character of Trajan's reign that attracted his early twentieth-century biographer, the Italian Fascist historian Roberto Paribeni, who in his 1927 two-volume biography Optimus Princeps described Trajan's reign as the acme of the Roman principate, which he saw as Italy's patrimony.^[291] Following in Paribeni's footsteps, the German historian Alfred Heuss saw in Trajan "the accomplished human embodiment of the imperial title" (die ideale Verkörperung des humanen Kaiserbegriffs).^[292] Trajan's first English-language biography by Julian Bennett is also a positive one in that it assumes that Trajan was an active policy-maker concerned with the management of the empire as a whole – something his reviewer Lendon considers an anachronistic outlook that sees in the Roman emperor a kind of modern administrator.^[293]

During the 1980s, the Romanian historian Eugen Cizek took a more nuanced view as he described the changes in the personal ideology of Trajan's reign, stressing the fact that it became ever more autocratic and militarized, especially after 112 and towards the Parthian War (as "only an universal monarch, a kosmocrator, could dictate his law to the East").^[294] The biography by the German historian Karl Strobel stresses the continuity between Domitian's and Trajan's reigns, saying that Trajan's rule followed the same autocratic and sacred character as Domitian's, culminating in a failed Parthian adventure intended as the crown of his personal achievement.^[295] It is in modern French historiography that Trajan's reputation becomes most markedly deflated: Paul Petit writes about Trajan's portraits as a "lowbrow boor with a taste for booze and boys".^[296] For Paul Veyne, what is to be retained from Trajan's "stylish" qualities was that he was the last Roman emperor to think of the empire as a purely Italian and Rome-centered hegemony of conquest. In contrast, his successor Hadrian would stress the notion of the empire as ecumenical and of the Emperor as universal benefactor and not kosmocrator.^[297]