The judiciary (also known as the judicial sister, judicature, judicial branch or court system) is the system of courts that interprets and applies the law in a country, state or an international community. The first legal systems of the world were set up to allow citizens to settle conflicts without violence.^[1]

The judiciary mainly interprets and applies the law, but can in some systems create law.

The judiciary is the system of courts that interprets and applies the law in the name of the state. The judiciary can also be thought of as the mechanism for the resolution of disputes. Under the doctrine of the separation of powers, the judiciary generally does not make statutory law (which is the responsibility of the legislature) or enforce law (which is the responsibility of the executive), but rather interprets law and applies it to the facts of each case. However, in some countries the judiciary does make common law.

In many jurisdictions the judicial branch has the power to change laws through the process of judicial review. Courts with judicial review power may annul the laws and rules of the state when it finds them incompatible with a higher norm, such as primary legislation, the provisions of the constitution, treaties or international law. Judges constitute a critical force for interpretation and implementation of a constitution, thus de facto in common law countries creating the body of constitutional law. For a people to establish and keep the 'Rule of Law' as the operative norm in social constructs great care must be taken in the election or appointment of unbiased and thoughtful legal scholars whose loyalty to an oath of office is without reproach. If law is to govern and find acceptance generally courts must exercise fidelity to justice which means affording those subject to its jurisdictional scope the greatest presumption of inherent cultural relevance within this framework.

The term "judiciary" is also used to refer collectively to the personnel, such as judges, magistrates and other adjudicators, who form the core of a judiciary (sometimes referred to as a "bench"), as well as the staffs who keep the system running smoothly. In some countries and jurisdictions, the judicial branch is expanded to include additional public legal professionals and institutions such as prosecutors, state lawyers, ombudsmen, public notaries, judicial police service and legal aid officers. These institutions are sometimes governed by the same judicial administration that governs courts, and in some cases the administration of the judicial branch is also the administering authority for private legal professions such as lawyers and private "notary" offices.

See also Legal History.

This is a more general overview of the development of the judiciary and judicial systems over the course of history.

See also Roman law and Byzantine Law.

When Rome first started to exist, law was given by the gods. The most important part was Ius Civile (latin for "civil law"). This consisted of Mos Maiorum (latin for "way of the ancestors") and Leges (latin for "laws"). Mos Maiorum was the rules of conduct based on social norms created over the years by predecessors. In 451-449 BC, the Mos Maiorum was written down in the Twelve Tables.^[2][3][4] Leges were rules set by the leaders, first the kings, later the popular assembly during the Republic. In these early years, the legal process consisted of two phases. The first phase, In Iure, was the judicial process. One would go to the head of the judicial system (at first the priests as law was part of religion) who would look at the applicable rules to the case. Parties in the case could be assisted by jurists.^[5] Then the second phase would start, the Apud Iudicem. The case would be put before the judges, which were normal Roman citizens in an uneven number. No experience was required as the applicable rules were already selected. They would merely have to judge the case.^[6]

The most important change in this period was the shift from priest to praetor as the head of the judicial system. The praetor would also make an edict in which he would declare new laws or principles for the year he was elected. This edict is also known as praetorian law.^[7][8]

The Principate is the first part of the Roman Empire, which started with the reign of Augustus. This time period is also known as the "classical era of Roman Law" In this era, the praetor's edict was now known as edictum perpetuum, which were all the edicts collected in one edict by Hadrian. Also, a new judicial process came up: cognitio extraordinaria (latin for "extraordinary process").^[9][10] This came into being due to the largess of the empire. This process only had one phase, where the case was presented to a professional judge who was a representative of the emperor. Appeal was possible to the immediate superior.

During this time period, legal experts started to come up. They studied the law and were advisors to the emperor. They also were allowed to give legal advise on behalf of the emperor.^[11]

This era is also known as the "post-classical era of roman law". The most important legal event during this era was the Codification by Justinianus: the Corpus Iuris Civilus.^[12] This contained all Roman Law. It was both a collection of the work of the legal experts and commentary on it, and a collection of new laws. The Corpus Iuris Civilus consisted of four parts:

See also Church Law

During the late Middle Ages, education started to grow. First education was limited to the monasteries and abbies, but expanded to cathedrals and schools in the city in the 11th century, eventually creating universities.^[13] The universities had five faculties: arts, medicine, theology, canon law and Ius Civile, or civil law. Canon law, or ecclesiastical law are laws created by the Pope, head of the Roman Catholic Church. The last form was also called secular law, or Roman law. It was mainly based on the Corpus Iuris Civilis, which had been rediscovered in 1070. Roman law was mainly used for "worldly" affairs, while canon law was used for questions related to the church.^[14]

The period starting in the 11th century with the discovery of the Corpus Iuris Civilis is also called the Scholastics, which can be divided in the early and late scholastics. It is characterised with the renewed interest in the old texts.

The rediscovery of the Digesta from the Corpus Iuris Civilis led the university of Bologna to start teaching Roman law.^[15] Professors at the university were asked to research the Roman laws and advise the Emperor and the Pope with regards to the old laws. This led to the Glossators to start translating and recreating the Corpus Iuris Civilis and create literature around it:

Accursius wrote the Glossa Ordinaria in 1263, ending the early scholastics.^[17]

The successors of the Glossators were the Post-Glossators or Commentators. They looked at a subject in a logical and systematic way by writing comments with the texts, treatises and consilia, which are advises given according to the old Roman law.^[18][19]

Canon law knows a few forms of laws: the canones, decisions made by Councils, and the decreta, decisions made by the Popes. The monk Gratian, one of the well-known decretists, started to organise all of the church law, which is now known as the Decretum Gratiani, or simply as Decretum. It forms the first part of the collection of six legal texts, which together became known as the Corpus Juris Canonici. It was used by canonists of the Roman Catholic Church until Pentecost (May 19) 1918, when a revised Code of Canon Law (Codex Iuris Canonici) promulgated by Pope Benedict XV on 27 May 1917 obtained legal force.^[20][21][22]

The Decretalists, like the post-glossators for Ius Civile, started to write treatises, comments and advises with the texts.^[23][24]

Around the 15th century a process of reception and acculturation started with both laws. The final product was known as Ius Commune. It was a combination of canon law, which represented the common norms and principles, and Roman law, which were the actual rules and terms. It meant the creation of more legal texts and books and a more systematic way of going through the legal process.^[25] In the new legal process, appeal was possible. The process would be partially inquisitorial, where the judge would actively investigate all the evidence before him, but also partially adversarial, where both parties are responsible for finding the evidence to convince the judge.^[26]

After the French Revolution, lawmakers stopped interpretation of law by judges, and the legislature was the only body permitted to interpret the law; this prohibition was later overturned by the Napoleonic Code.^[29]

In common law jurisdictions, courts interpret law; this includes constitutions, statutes, and regulations. They also make law (but in a limited sense, limited to the facts of particular cases) based upon prior case law in areas where the legislature has not made law. For instance, the tort of negligence is not derived from statute law in most common law jurisdictions. The term common law refers to this kind of law. Common law decisions set precedent for all courts to follow. This is sometimes called stare decisis.

In civil law jurisdictions, courts interpret the law, but are prohibited from creating law, and thus do not issue rulings more general than the actual case to be judged. In other words, they do not set precedent. Jurisprudence does not necessarily play a similar role to case law. Courts can decide if they follow jurisprudence in a given case or not.

In the United States court system, the Supreme Court is the final authority on the interpretation of the federal Constitution and all statutes and regulations created pursuant to it, as well as the constitutionality of the various state laws; in the US federal court system, federal cases are tried in trial courts, known as the US district courts, followed by appellate courts and then the Supreme Court. State courts, which try 98% of litigation,^[30] may have different names and organization; trial courts may be called "courts of common plea", appellate courts "superior courts" or "commonwealth courts".^[31] The judicial system, whether state or federal, begins with a court of first instance, is appealed to an appellate court, and then ends at the court of last resort.^[32]

In France, the final authority on the interpretation of the law is the Council of State for administrative cases, and the Court of Cassation for civil and criminal cases.

In the People's Republic of China, the final authority on the interpretation of the law is the National People's Congress.

Other countries such as Argentina have mixed systems that include lower courts, appeals courts, a cassation court (for criminal law) and a Supreme Court. In this system the Supreme Court is always the final authority, but criminal cases have four stages, one more than civil law does. On the court sits a total of nine justices. This number has been changed several times.

Japan's process for selecting judges is longer and more stringent than in various countries, like the United States and in Mexico.^[33] Assistant judges are appointed from those who have completed their training at the Legal Training and Research Institute located in Wako. Once appointed, assistant judges still may not qualify to sit alone until they have served for five years, and have been appointed by the Supreme Court of Japan. Judges require ten years of experience in practical affairs, as a public prosecutor or practicing attorney. In the Japanese judicial branch there is the Supreme Court, eight high courts, fifty district courts, fifty family courts, and 438 summary courts.^[34][35]

Justices of the Mexican Supreme Court are appointed by the President of Mexico, and then are approved by the Mexican Senate to serve for a life term. Other justices are appointed by the Supreme Court and serve for six years. Federal courts consist of the 21 magistrates of the Supreme Court, 32 circuit tribunals and 98 district courts. The Supreme Court of Mexico is located in Mexico City. Supreme Court Judges must be of ages 35 to 65 and hold a law degree during the five years preceding their nomination.^[36]

United States Supreme Court justices are appointed by the President of the United States and approved by the United States Senate. The Supreme Court justices serve for a life term or until retirement. The Supreme Court is located in Washington, D.C. The United States federal court system consists of 94 federal judicial districts. The 94 districts are then divided up into twelve regional circuits. The United States has five different types of courts that are considered subordinate to the Supreme Court: United States bankruptcy courts, United States Court of Appeals for the Federal Circuit, United States Court of International Trade, United States courts of appeals, and United States district courts.^[37][38]

Immigration courts are not part of the judicial branch; immigration judges are employees of the Executive Office for Immigration Review, part of the United States Department of Justice in the executive branch.