The Eastern Catholic Churches or Oriental Catholic Churches, also called the Eastern-rite Catholic Churches, and in some historical cases Uniate Churches,^[12] are twenty-three Eastern Christian particular churches sui iuris in full communion with the Pope in Rome, as part of the worldwide Catholic Church. Headed by patriarchs, metropolitans, and major archbishops, the Eastern Catholic Churches are governed in accordance with the Code of Canons of the Eastern Churches, although each church also has its own canons and laws on top of this, and the preservation of their own traditions is explicitly encouraged. The total membership of the various churches accounts for about 18 million, according to the Annuario Pontificio (the annual directory of the Catholic Church), thus making up about 1.5 percent of the Catholic Church, with the rest of its more than 1.3 billion members belonging to the Latin Church, also known as the Western Church or the Roman Catholic Church.

The Maronite Church is considered the only one of the Eastern Catholic Churches to have always remained in full communion with the Holy See, while most of the other churches unified from the 16th century onwards. However, the Melkite Catholic Church and the Italo-Albanian Greek Catholic Church also claim perpetual communion. The largest six churches based on membership are: the Ukrainian Greek Catholic Church (Byzantine Rite), the Syro-Malabar Church (East Syriac Rite), the Maronite Church (West Syriac Rite), the Melkite Catholic Church (Byzantine Rite), the Chaldean Catholic Church (East Syriac Rite) and the Armenian Catholic Church (Armenian Rite). These six churches account for about 85% of the membership of the Eastern Catholic Churches.

Full communion constitutes mutual sacramental sharing between the Eastern Catholic Churches and the Latin Church, including Eucharistic intercommunion. On the other hand, the liturgical traditions of the 23 Eastern Catholic churches, including Byzantine, Alexandrian, Armenian, East Syriac, and West Syriac, are shared with other Eastern Christian churches: the Eastern Orthodox, Oriental Orthodox, the Assyrian Church of the East, and the Ancient Church of the East. Although some theological issues divide the Eastern Catholic Churches from other Eastern Christian ones, they do admit members of the latter to the Eucharist and the other sacraments, as governed by Oriental canon law.^[13]

Notably, many of the Eastern Catholic Churches take a different approach to clerical celibacy than the Latin Church does and allow the ordination of married men to the priesthood (although not to the episcopacy).

Eastern Catholic Churches have their origins in the Middle East, East Africa, Eastern Europe and India. However, since the 19th century, diaspora has spread to Western Europe, the Americas and Oceania in part because of persecution, where eparchies have been established to serve adherents alongside those of Latin Church dioceses. Latin Catholics in the Middle East, on the other hand, are traditionally cared for by the Latin Patriarchate of Jerusalem.

Although Eastern Catholics are in full communion with the Pope and members of the worldwide Catholic Church,^[14][15] they are not members of the Latin Church, which uses the Latin liturgical rites, among which the Roman Rite is the most widespread.^[16] The Eastern Catholic churches are instead distinct particular churches sui iuris, although they maintain full and equal, mutual sacramental exchange with members of the Latin Church.

There are different meanings of the word rite. Apart from its reference to the liturgical patrimony of a particular church, the word has been and is still sometimes, even if rarely, officially used of the particular church itself. Thus the term Latin rite can refer either to the Latin Church or to one or more of the Western liturgical rites, which include the majority Roman Rite but also the Ambrosian Rite, the Mozarabic Rite, and others.

In the 1990 Code of Canons of the Eastern Churches (CCEO),^[30][31] the terms autonomous Church and rite are thus defined:

When speaking of Eastern Catholic Churches, the Latin Church's 1983 Code of Canon Law (1983 CIC) uses the terms "ritual Church" or "ritual Church sui iuris" (canons 111 and 112), and also speaks of "a subject of an Eastern rite" (canon 1015 §2), "Ordinaries of another rite" (canon 450 §1), "the faithful of a specific rite" (canon 476), etc. The Second Vatican Council spoke of Eastern Catholic Churches as "particular Churches or rites".^{[34] []}

In 1999, the United States National Conference of Catholic Bishops stated: "We have been accustomed to speaking of the Latin (Roman or Western) Rite or the Eastern Rites to designate these different Churches. However, the Church's contemporary legislation as contained in the Code of Canon Law and the Code of Canons of the Eastern Churches makes it clear that we ought to speak, not of rites, but of Churches. Canon 112 of the Code of Canon Law uses the phrase 'autonomous ritual Churches' to designate the various Churches."^[35] And a writer in a periodical of January 2006 declared: "The Eastern Churches are still mistakenly called 'Eastern-rite' Churches, a reference to their various liturgical histories. They are most properly called Eastern Churches, or Eastern Catholic Churches."^[36] However, the term "rite" continues to be used. The 1983 CIC forbids a Latin bishop to ordain, without permission of the Holy See, a subject of his who is "of an Eastern rite" (not "who uses an Eastern rite", the faculty for which is sometimes granted to Latin clergy).^[37] Pope Benedict XVI wrote, in his 2007 motu proprio Summorum Pontificum, that "any Catholic priest of the Latin rite",^[17] under certain conditions, "may use either" edition of the Roman Missal.^[39]

The term Uniat or Uniate applies to Eastern Catholic churches previously part of Eastern or Oriental Orthodox churches or of the Assyrian Church of the East. The term is sometimes considered to have a derogatory connotation,^[24][25] though it was occasionally used by Latin and Eastern Catholics prior to the Second Vatican Council.^[18] Official Catholic documents no longer use the term due to its perceived negative overtones.^[25] According to John Erickson of Saint Vladimir's Orthodox Theological Seminary,

Communion between Christian churches has been broken over matters of faith, whereby each side accused the other of heresy or departure from the true faith (orthodoxy). Communion has been broken also because of disagreement about questions of authority or the legitimacy of the election of a particular bishop. In these latter cases each side accused the other of schism, but not of heresy.

The following ecumenical councils are major breaches of communion:

In 431 the Churches that accepted the teaching of the Council of Ephesus (which condemned the views of Nestorius) classified as heretics those who rejected the Council's statements. The Church of the East, which was mainly under the Sassanid Empire, never accepted the council's views. It later experienced a period of great expansion in Asia before collapsing after the Mongol invasion of the Middle East in the 14th century.

Monuments of their presence still exist in China. Now they are relatively few in number and have divided into three Churches: the Chaldean Catholic Church—an Eastern Catholic Church in full communion with Rome—and two Assyrian Churches which are not in communion with either Rome or each other. The Chaldean Catholic Church is the largest of the three. The groups of Assyrians who did not reunify with Rome remained and are known as the Assyrian Church of the East, which experienced an internal schism in 1968 which led to the creation of the Ancient Church of the East.

In 451 those who accepted the Council of Chalcedon similarly classified those who rejected it as Monophysite heretics. The Churches that refused to accept the Council considered instead that it was they who were orthodox; they reject the description Monophysite (meaning only-nature) preferring instead Miaphysite (meaning one-nature). The difference in terms may appear subtle, but it is theologically very important. "Monophysite" implies a single divine nature alone with no real human nature - a heretical belief according to Chalcedonian Christianity - whereas "Miaphysite" can be understood to mean one nature as God, existing in the person of Jesus who is both human and divine - an idea more easily reconciled to Chalcedonian doctrine. They are often called, in English, Oriental Orthodox Churches, to distinguish them from the Eastern Orthodox Churches.

This distinction, by which the words oriental and eastern that in themselves have exactly the same meaning but are used as labels to describe two different realities, is impossible to translate in most other languages, and is not universally accepted even in English. These churches are also referred to as pre-Chalcedonian or now more rarely as non-Chalcedonian or anti-Chalcedonian. In languages other than English other means are used to distinguish the two families of Churches. Some reserve the term "Orthodox" for those that are here called "Eastern Orthodox" Churches, but members of what are called "Oriental Orthodox" Churches consider this illicit.

The East–West Schism came about in the context of cultural differences between the Greek-speaking East and Latin-speaking West and of rivalry between the Churches in Rome, which claimed a primacy not merely of honour but also of authority—and in Constantinople, which claimed parity with Rome.^[43] The rivalry and lack of comprehension gave rise to controversies, some of which appear already in the acts of the Quinisext Council of 692. At the Council of Florence (1431–1445), these controversies about Western theological elaborations and usages were identified as, chiefly, the insertion of "Filioque" into the Nicene Creed, the use of unleavened bread for the Eucharist, Purgatory, and the authority of the Pope.^[19]

The schism is conventionally dated as occurring at 1054, when the Patriarch of Constantinople, Michael I Cerularius, and the Papal Legate, Humbert of Silva Candida, issued mutual excommunications. (In 1965 these excommunications were revoked by both Rome and Constantinople.) In spite of that event, for many years both Churches continued to maintain friendly relations and seemed to be unaware of any formal or final rupture.^[45]

However, estrangement continued to grow. In 1190, Eastern Orthodox theologian Theodore Balsamon who was patriarch of Antioch, wrote that "no Latin should be given Communion unless he first declares that he will abstain from the doctrines and customs that separate him from us".^[46]

Later, Constantinople was sacked in 1204 by the Catholic armies of the Fourth Crusade, whereas two decades previously the Massacre of the Latins (i.e. Catholics) had occurred in Constantinople in 1182. Thus, by the 12th–13th centuries, the two sides had become openly hostile, each considering that the other no longer belonged to the Church that was orthodox and catholic. Over time, it became customary to refer to the Eastern side as the Orthodox Church and the Western as the Catholic Church, without either side thereby renouncing its claim to be the truly orthodox or the truly catholic Church.

Within each Church, no longer in communion with the Church of Rome, there arose a group that considered it important to restore that communion. In 1438, the Council of Florence convened, which featured a strong dialogue focused on understanding the theological differences between the East and West, with the hope of reuniting the Catholic and Orthodox churches.^[47] Several eastern churches associated themselves with Rome, forming Eastern Catholic Churches. The See of Rome accepted them without requiring that they adopt the customs of the Latin Church, so that they all have their own "liturgical, theological, spiritual and disciplinary heritage, differentiated by peoples' culture and historical circumstances, that finds expression in each sui iuris Church's own way of living the faith".^[48]

In 1993 the Joint International Commission for Theological Dialogue Between the Catholic Church and the Orthodox Church submitted the document Uniatism, method of union of the past, and the present search for full communion, also known as the Balamand declaration, "to the authorities of the Catholic and Orthodox Churches for approval and application,"^[49] which stated that initiatives that "led to the union of certain communities with the See of Rome and brought with them, as a consequence, the breaking of communion with their Mother Churches of the East ... took place not without the interference of extra-ecclesial interests".^{[49] []}

Likewise the commission acknowledged that "certain civil authorities [who] made attempts" to force Eastern Catholics to return to the Orthodox Church used "unacceptable means".^{[49] []} The missionary outlook and proselytism that accompanied the Unia^{[49] []} was judged incompatible with the rediscovery by the Catholic and Orthodox Churches of each other as Sister Churches.^{[49] []} Thus the commission concluded that the "missionary apostolate ..., which has been called 'uniatism', can no longer be accepted either as a method to be followed or as a model of the unity our Churches are seeking."^{[49] []}

At the same time, the Commission stated:

Most Eastern Catholic churches arose when a group within an ancient church in disagreement with the See of Rome returned to full communion with that see. The following Churches have been in communion with the Bishop of Rome for a large part of their history:

The canon law shared by all Eastern Catholic churches, CCEO, was codified in 1990. The dicastery that works with the Eastern Catholic churches is the Congregation for the Oriental Churches which, by law, includes as members all Eastern Catholic patriarchs and major archbishops.

On 30 November 1894 Pope Leo XIII issued the apostolic constitution Orientalium dignitas in which he stated:

Adrian Fortescue wrote that Leo XIII "begins by explaining again that the ancient Eastern rites are a witness to the Apostolicity of the Catholic Church, that their diversity, consistent with unity of the faith, is itself a witness to the unity of the Church, that they add to her dignity and honour. He says that the Catholic Church does not possess one rite only, but that she embraces all the ancient rites of Christendom; her unity consists not in a mechanical uniformity of all her parts, but on the contrary, in their variety, according in one principle and vivified by it."^[51]

Leo XIII declared still in force Pope Benedict XIV's encyclical Demandatam, addressed to the Patriarch and the Bishops of the Melkite Catholic Church, in which Benedict XIV forbade Latin Rite clergy to induce Melkite Catholics to transfer to the Latin rite, and he broadened this prohibition to cover all Eastern Catholics, declaring: "Any Latin rite missionary, whether of the secular or religious clergy, who induces with his advice or assistance any Eastern rite faithful to transfer to the Latin rite, will be deposed and excluded from his benefice in addition to the ipso facto suspension a divinis and other punishments that he will incur as imposed in the aforesaid Constitution Demandatam."^[50]

There had been confusion on the part of Western clergy about the legitimate presence of Eastern Catholic Churches in countries seen as belonging to the West, despite firm and repeated papal confirmation of these Churches' universal character. The Second Vatican Council brought the reform impulse to visible fruition. Several documents, from both during and after the Second Vatican Council, have led to significant reform and development within Eastern Catholic Churches.

The Second Vatican Council directed, in Orientalium Ecclesiarum, that the traditions of Eastern Catholic Churches should be maintained. It declared that "it is the mind of the Catholic Church that each individual Church or Rite should retain its traditions whole and entire and likewise that it should adapt its way of life to the different needs of time and place" (n. 2), and that they should all "preserve their legitimate liturgical rite and their established way of life, and ... these may not be altered except to obtain for themselves an organic improvement" (n. 6; cf. n. 22).^[34]

It confirmed and approved the ancient discipline of the sacraments existing in the Eastern churches, and the ritual practices connected with their celebration and administration, and declared its ardent desire that this should be re-established, if circumstances warranted (n. 12). It applied this in particular to administration of sacrament of Confirmation by priests (n. 13). It expressed the wish that, where the permanent diaconate (ordination as deacons of men who are not intended afterwards to become priests) had fallen into disuse, it should be restored (n. 17).

Paragraphs 7–11 are devoted to the powers of the patriarchs and major archbishops of the Eastern Churches, whose rights and privileges, it says, should be re-established in accordance with the ancient tradition of each of the Churches and the decrees of the ecumenical councils, adapted somewhat to modern conditions. Where there is need, new patriarchates should be established either by an ecumenical council or by the Bishop of Rome.

The Second Vatican Council's Dogmatic Constitution on the Church, Lumen gentium, deals with Eastern Catholic Churches in paragraph 23, stating:

The 1964 decree Unitatis redintegratio deals with Eastern Catholic Churches in paragraphs 14–17.^[53]

The First Vatican Council discussed the need for a common code for the Eastern Churches, but no concrete action was taken. Only after the benefits of the Latin Church's 1917 Code of Canon Law were appreciated was a serious effort made to codify Eastern Catholic Churches canon laws.^{[54] []} This came to fruition with the promulgation of the 1990 Code of Canons of the Eastern Churches, which took effect in 1991. It is a framework document that contains canons that are a consequence of the common patrimony of the Churches of the East: each individual sui iuris Church also has its own canons, its own particular law, layered on top of this code.

The 1996 Instruction for Applying the Liturgical Prescriptions of the Code of Canons of the Eastern Churches brought together, in one place, the developments that took place in previous texts,^[55] and is "an expository expansion based upon the canons, with constant emphasis upon the preservation of Eastern liturgical traditions and a return to those usages whenever possible—certainly in preference to the usages of the Latin Church, however much some principles and norms of the conciliar constitution on the Roman rite, "in the very nature of things, affect other rites as well."^{[54] []} The Instruction states:

Past interventions by the Holy See, the Instruction said, were in some ways defective and needed revision, but often served also as a safeguard against aggressive initiatives.

Under the Code of Canons of the Eastern Churches, the Pope has supreme, full, immediate and universal ordinary authority in the whole Catholic Church, which he can always freely exercise, including the Eastern Catholic churches,^[56][21] and their leaders.^[58]

The Catholic patriarchs and major archbishops derive their titles from the sees of Alexandria (Coptic), Antioch (Syriac, Melkite, Maronite), Babylonia (Chaldaean), Cilicia (Armenian), Kiev-Halych (Ukrainian), Ernakulam-Angamaly (Syro-Malabar), Thiruvananthapuram (Syro-Malankara), and Făgăraş-Alba Iulia (Romanian). The Eastern Catholic churches are governed in accordance with Code of Canons of the Eastern Churches.^[58]

Within their proper sui iuris churches there is no difference between patriarchs and major archbishops. However, differences exist in the order of precedence (i.e. patriarchs take precedence over major archbishops) and in the mode of accession: The election of a major archbishop has to be confirmed by the pope before he may take office.^[59] No papal confirmation is needed for newly-elected patriarchs before they take office. They are just required to request as soon as possible that the pope grant them full ecclesiastical communion.^[60][22]

There are significant differences between various Eastern Catholic churches, regarding their present organizational structure. Major Eastern Catholic churches, that are headed by their patriarchs, major archbishops or metropolitans, have fully developed structure and functioning internal autonomy based on the existence of ecclesiastical provinces. On the other hand, minor Eastern Catholic churches often have only one or two hierarchs (in the form of eparchs, apostolic exarchs, or apostolic visitors) and only the most basic forms of internal organization if any, like the Belarusian Greek Catholic Church or the Russian Greek Catholic Church.^[62] Individual eparchies of some Eastern Catholic churches may be suffragan to Latin-rite metropolitans. For example, the Greek Catholic Eparchy of Križevci is suffragan to the Roman Catholic Archdiocese of Zagreb.^[63] Also, some minor Eastern Catholic churches have Latin prelates. For example, the Macedonian Greek Catholic Church is organized as a single Eparchy of Strumica-Skopje, whose present ordinary is the Roman Catholic bishop of Skopje.^[64] The organization of the Albanian Greek Catholic Church is unique in that it comprises an "Apostolic Administration".^[65]

Although every diocese in the Catholic Church is considered a particular church, the word is not applied in the same sense as to the 24 sui iuris particular churches: the Latin Church and the 23 Eastern Catholic Churches.

Canonically, each Eastern Catholic Church is sui iuris or autonomous with respect to other Catholic churches, whether Latin or Eastern, though all accept the spiritual and juridical supreme authority of the pope. Thus a Maronite Catholic is normally directly subject only to a Maronite bishop. However, if members of a particular church are so few that no hierarchy of their own has been established, their spiritual care is entrusted to a bishop of another ritual church. For instance, members of the Latin Church in Eritrea are under the care of the Eastern rite Eritrean Catholic Church, whereas the other way around may be the case in other parts of the world.

Theologically, all the particular churches can be viewed as "sister churches".^[66] According to the Second Vatican Council these Eastern Catholic churches, along with the larger Latin Church, share "equal dignity, so that none of them is superior to the others as regards rite, and they enjoy the same rights and are under the same obligations, also in respect of preaching the Gospel to the whole world (cf. Mark 16:15 ^[105] ) under the guidance of the Roman Pontiff."^{[34] []}

The Eastern Catholic churches are in full communion with the whole Catholic Church. While they accept the canonical authority of the Holy See of Rome, they retain their distinctive liturgical rites, laws, customs and traditional devotions, and have their own theological emphases. Terminology may vary: for instance, diocese and eparchy, vicar general and protosyncellus, confirmation and chrismation are respectively Western and Eastern terms for the same realities. The mysteries (sacraments) of baptism and chrismation are generally administered, according to the ancient tradition of the church, one immediately after the other. Infants who are baptized and chrismated are also given the Eucharist.^[67]

The Eastern Catholic churches are represented in the Holy See and the Roman Curia through the Congregation for the Oriental Churches, which is "made up of a Cardinal Prefect (who directs and represents it with the help of a Secretary) and 27 cardinals, one archbishop and 4 bishops, designated by the pope ad quinquennium (for a five-year period). Members by right are the Patriarchs and the Major Archbishops of the Oriental Churches and the President of the Pontifical Council for the Promotion of Unity among Christians."^[68]

Totalling about 16 million members, the greatest numbers of Eastern Catholics may be found in Eastern Europe (Ukraine, Romania, Slovakia), Eastern Africa and the Middle East (Egypt, Iraq, Lebanon, Syria) and India.

While "clerics and members of institutes of consecrated life are bound to observe their own rite faithfully",^[69] priests are occasionally given permission to celebrate the liturgy of a rite other than the priest's own rite, by what is known as a grant of "biritual faculties". The reason for this permission is usually the service of Catholics who have no priest of their own rite. Thus priests of the Syro-Malabar Church working as missionaries in areas of India in which there are no structures of their own Church, are authorized to use the Roman Rite in those areas, and Latin-Rite priests are, after due preparation, given permission to use an Eastern rite for the service of members of an Eastern Catholic Church living in a country in which there are no priests of their own particular Church. Popes are permitted to celebrate a Mass or Divine Liturgy of any rite in testament to the Catholic Church's universal nature. John Paul II celebrated the Divine Liturgy in Ukraine during his pontificate.

For a just cause, and with the permission of the local bishop, priests of different autonomous ritual Churches may concelebrate; however, the rite of the principal celebrant is used whilst each priest wears the vestments of his own rite.^[70] No indult of bi-ritualism is required for this.

Biritual faculties may concern not only clergy but also religious, enabling them to become members of an institute of an autonomous Church other than their own.^[71]

The laity is typically encouraged to foster an appreciation of their own rite, and is invited to observe that rite unless there is good reason, e.g. Latin-Rite Catholics living in an exclusively Ethiopian Rite country.^[72] This does not forbid occasional or even, for a just cause, habitual participation in the liturgy of a different autonomous Church, Western or Eastern. The obligation of assisting at the Eucharist or, for members of some Eastern Churches, at Vespers, is satisfied wherever the liturgy is celebrated in a Catholic rite.^[73]

Eastern and Western Christian churches have different traditions concerning clerical celibacy and the resulting controversies have played a role in the relationship between the two groups in some Western countries.

In general, Eastern Catholic Churches have always allowed ordination of married men as priests and deacons. Within the lands of the Ukrainian Greek Catholic Church, the largest Eastern Catholic Church, priests' children often became priests and married within their social group, establishing a tightly-knit hereditary caste.^[74]

Most Eastern Churches distinguish between "monastic" and "non-monastic" clergy. Monastics do not necessarily live in monasteries, but have spent at least part of their period of training in such a context. Their monastic vows include a vow of celibate chastity.

Bishops are normally selected from the monastic clergy, and in most Eastern Catholic Churches a large percentage of priests and deacons also are celibate, while a large portion of the clergy (typically, parish priests) are married, having taken a wife when they were still laymen.^[74] If someone preparing for the diaconate or priesthood wishes to marry, this must happen before ordination.

In territories where Eastern traditions prevail, married clergy caused little controversy, but aroused opposition inside traditionally Latin Church territories to which Eastern Catholics migrated; this was particularly so in the United States. In response to requests from the Latin bishops of those countries, the Congregation for the Propagation of the Faith set out rules in an 1890 letter to François-Marie-Benjamin Richard, archbishop of Paris,^[75] which the Congregation applied on 1 May 1897 to the United States,^[76] stating that only celibates or widowed priests coming without their children should be permitted in the United States.

This celibacy mandate for Eastern Catholic priests in the United States was restated with special reference to Catholics of Ruthenian Rite by the 1 March 1929 decree Cum data fuerit, which was renewed for a further ten years in 1939. Dissatisfaction by many Ruthenian Catholics in the United States gave rise to the American Carpatho-Russian Orthodox Diocese.^[77] The mandate, which applied in some other countries also, was removed by a decree of June 2014.^[78]

While most Eastern Catholic Churches admit married men to ordination as priests (although not allowing priests to marry after ordination), some have adopted mandatory clerical celibacy, as in the Latin Church. These include the India-based Syro-Malankara Catholic Church and Syro-Malabar Catholic Church,^[79][80] and the Coptic Catholic Church.^[81]

In 2014, Pope Francis approved new norms for married clergy within Eastern Catholic Churches through CCEO canon 758 § 3. The new norms abrogated previous norms and now allow those Eastern Catholic Churches with married clergy to ordain married men inside traditionally Latin territories and to grant faculties inside traditionally Latin territories to married Eastern Catholic clergy previously ordained elsewhere.^[82] This latter change will allow married Eastern Catholic priests to follow their faithful to whatever country they may immigrate to, addressing an issue which has arisen with the exodus of so many Christians from Eastern Europe and the Middle East in recent decades.^[83]

The Holy See's Annuario Pontificio gives the following list of Eastern Catholic churches with the principal Episcopal See of each and the countries (or larger political areas) where they have ecclesiastical jurisdiction, to which are here added the date of union or foundation in parenthesis and the membership in brackets. The total membership for all Eastern Catholic Churches is at least 16,336,000 people. Eternal Word Television Network (EWTN) gives the same list, except that it does not place the liturgical traditions in the alphabetical order in which they are given by both the Annuario Pontificio and CCEO canon 28 ^[106] , and, as noted below, it treats the Apostolic Exarchate for Byzantine-Rite Catholics in the Czech Republic, which for the Holy See is part of the Ruthenian Catholic Church, as if it were a separate autonomous church.^[84]

Eastern Catholic Churches make up a small percentage of the membership in the Catholic Church when compared to the Latin Church, which has over 1.2 billion members. The 2017 statistics collected by the Catholic Near East Welfare Association (CNEWA) show that the four largest Eastern Catholic Churches are the Ukrainian Greek Catholic Church with 4.5 million members (roughly 25% of all Eastern Catholics), the Syro-Malabar Catholic Church with 4.3 million members (24%), the Maronite Church with 3.5 million members (20%), and the Melkite Greek Catholic Church with 1.6 million members (9%).^[86]

The list shows that an individual autonomous particular church may have distinct jurisdictions (local particular churches) in several countries.

The Ruthenian Greek Catholic Church is organized in an exceptional way because of a constituent metropolia: the Ruthenian Catholic Metropolitan Church of Pittsburgh in Pennsylvania, United States. The latter is also, unofficially, referred to as the Byzantine Catholic Church in America. Canon law treats it as if it held the rank of an autonomous (sui iuris) metropolitan particular church because of the circumstances surrounding its 1969 establishment as an ecclesiastical province. At that time, conditions in the Rusyn homeland, known as Carpatho-Rus, were such that the Byzantine Catholic Church had been forcibly suppressed by the Soviet authorities. When Communist rule ended, the Greek Catholic Eparchy of Mukachevo (founded in 1771) re-emerged. As of the early 21st century, it has some 320,000 adherents, greater than the number in the Pittsburgh metropolia. In addition, an apostolic exarchate established in 1996 for Catholics of Byzantine rite in the Czech Republic is classed as another part of the Ruthenian Catholic Church.

On the EWTN website, the Ruthenian Catholic Apostolic Exarchate of Czech Republic is mentioned in a list of Eastern Churches, of which all the rest are autonomous particular churches.^[84] This is a mistake, since recognition within the Catholic Church of the autonomous status of a particular church can only be granted by the Holy See.^[23] It classifies this church as one of the constituent local particular churches of the autonomous (sui iuris) Ruthenian Catholic Church.

A study by Methodios Stadnik states: "The Georgian Byzantine Catholic Exarch, Fr. Shio Batmanishviii [sic], and two Georgian Catholic priests of the Latin Church were executed by the Soviet authorities in 1937 after having been held in captivity in Solovki prison and the northern gulags from 1923."^[91] Christopher Zugger writes, in The Forgotten: "By 1936, the Byzantine Catholic Church of Georgia had two communities, served by a bishop and four priests, with 8,000 believers", and he identifies the bishop as Shio Batmalashvili.^[92] Vasyl Ovsiyenko mentions, on the Ukrainian Helsinki Human Rights Union website, that "the Catholic administrator for Georgia Shio Batmalashvili" was one of those executed as "anti-Soviet elements" in 1937.^[93]

Zugger calls Batmalashvili a bishop; Stadnik is ambiguous, calling him an exarch but giving him the title of Father; Ovsiyenko merely refers to him as "the Catholic administrator" without specifying whether he was a bishop or a priest and whether he was in charge of a Latin or a Byzantine jurisdiction.

If Batmalashvili was an exarch, and not instead a bishop connected with the Latin diocese of Tiraspol, which had its seat at Saratov on the Volga River, to which Georgian Catholics even of Byzantine rite belonged ^[94] this would mean that a Georgian Byzantine-Rite Catholic Church existed, even if only as a local particular Church. However, since the establishment of a new hierarchical jurisdiction must be published in Acta Apostolicae Sedis, and no mention of the setting up of such a jurisdiction for Byzantine Georgian Catholics exists in that official gazette of the Holy See, the claim appears to be unfounded.

The 1930s editions of Annuario Pontificio do not mention Batmalashvili. If indeed he was a bishop, he may then have been one of those secretly ordained for the service of the Church in the Soviet Union by French Jesuit Bishop Michel d'Herbigny, who was president of the Pontifical Commission for Russia from 1925 to 1934. In the circumstances of that time, the Holy See would have been incapable of setting up a new Byzantine exarchate within the Soviet Union, since Byzantine Catholics in the Soviet Union were being forced to join the Russian Orthodox Church.

Batmalashvili's name is not among those given in as the four "underground" apostolic administrators (only one of whom appears to have been a bishop) for the four sections into which the diocese of Tiraspol was divided after the resignation in 1930 of its already exiled last bishop, Josef Alois Kessler.^[95] This source gives Father Stefan Demurow as apostolic administrator of "Tbilisi and Georgia" and says he was executed in 1938. Other sources associate Demurow with Azerbaijan and say that, rather than being executed, he died in a Siberian Gulag.^[96]

Until 1994, the United States annual publication Catholic Almanac listed "Georgian" among the Byzantine churches.^[97] Until corrected in 1995, it appears to have been making a mistake similar to that made on the equally unofficial EWTN site about the Czech Byzantine Catholics.

There was a short-lived Byzantine Catholic movement among the ethnic Estonians in the Orthodox Church in Estonia during the interwar period of the 20th century, consisting of two to three parishes, not raised to the level of a local particular church with its own head. This group was liquidated by the Soviet regime and is now extinct.

Since the American invasion of Iraq, Christians have faced increasing levels of persecution in the Islamic world. Previously, the secular governments in Iraq, Syria and other nations protected their Christian minorities. Muslim, Jewish and South Asian nations in which Christian populations have suffered acute discrimination, persecution and in some cases death include; Iraq, Iran, Israel, Syria, Palestinian Territories, Egypt, Saudi Arabia, Turkey, Qatar, Uzbekistan, Jordan, Oman, Kuwait, Kazakhstan, Tajikistan, Turkmenistan, Kyrgyzstan, Eritrea, United Arab Emirates, Kosovo, Chechnya.^[98][99]

While not subject to the kind of physical dangers or persecution from government authorities encountered in Eastern Europe or the Middle East, adherents of Eastern Catholic Churches in United States, most of whom were relatively new immigrants from Eastern Europe, encountered difficulties due to hostility from the Latin Rite clergy who dominated the Catholic hierarchy in United States who found them alien. In particular, immigration of Eastern Rite priests who were married, common in their churches but extremely rare in Latin churches, was forbidden or severely limited and some Latin rite bishops actively interfered with the pastoral work of those who did arrive. Some bishops sought to forbid all non-Latin Catholic priests from coming to United States at all. Many Eastern Catholic immigrants to United States were thus either assimilated into the Latin Rite or joined the Eastern Orthodox Church. One former Eastern Catholic priest, Alexis Toth, is well-known for having abandoned Catholicism after difficult experience with John Ireland, the Latin bishop of Saint Paul, and joining the Orthodox Church, in which he has been canonized as a saint for having led as many as 20,000 disaffected former Eastern Catholics to the Orthodox Church.