The judiciary (also known as the judicial system, judicature, judicial branch, judiciative branch, and court or judiciary system) is the system of
court A court is any person or institution, often as a government institution, with the authority to adjudicate legal disputes between parties and carry out the administration of justice in civil, criminal, and administrative matters in ac ...
s that adjudicates legal disputes/disagreements and interprets, defends, and applies the law in legal cases.


The judiciary is the system of courts that interprets, defends, 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, defends, and applies the law to the facts of each case. However, in some countries the judiciary does make
common law In law, common law (also known as judicial precedent, judge-made law, or case law) is the body of law created by judges and similar quasi-judicial tribunals by virtue of being stated in written opinions."The common law is not a brooding omnipres ...
. In many
jurisdiction Jurisdiction (from Latin 'law' + 'declaration') is the legal term for the legal authority granted to a legal entity to enact justice. In federations like the United States, areas of jurisdiction apply to local, state, and federal levels. J ...
s the judicial branch has the power to change laws through the process of
judicial review Judicial review is a process under which executive, legislative and administrative actions are subject to review by the judiciary. A court with authority for judicial review may invalidate laws, acts and governmental actions that are inco ...
. 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 A constitution is the aggregate of fundamental principles or established precedents that constitute the legal basis of a polity, organisation or other type of entity An entity is something that exists as itself, as a subject or as an ...
, treaties or international law. Judges constitute a critical force for interpretation and implementation of a constitution, thus in
common law In law, common law (also known as judicial precedent, judge-made law, or case law) is the body of law created by judges and similar quasi-judicial tribunals by virtue of being stated in written opinions."The common law is not a brooding omnipres ...
countries creating the body of constitutional law.


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

Roman judiciary

Archaic Roman Law (650–264 BC)

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 The Laws of the Twelve Tables was the legislation that stood at the foundation of Roman law Roman law is the law, legal system of ancient Rome, including the legal developments spanning over a thousand years of jurisprudence, from the Twelve ...
. ''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. 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.

Pre-classical Roman Law (264–27 BC)

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.

Principate (27 BC–284 AD)

The Principate is the first part of the Roman Empire, which started with the reign of
Augustus Caesar Augustus (born Gaius Octavius; 23 September 63 BC – 19 August AD 14), also known as Octavian, was the first Roman emperor; he reigned from 27 BC until his death in AD 14. He is known for being the founder of the Roman Pr ...
. 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 Hadrian (; la, Caesar Trâiānus Hadriānus ; 24 January 76 – 10 July 138) was Roman emperor from 117 to 138. He was born in Italica (close to modern Santiponce in Spain), a Roman '' municipium'' founded by Italic settlers in Hispan ...
. Also, a new judicial process came up: ''cognitio extraordinaria'' (Latin for "extraordinary process"). 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.

Dominate (284–565 AD)

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 Civilis. 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 Civilis'' consisted of four parts: # ''Institutiones'': This was an introduction and a summary of Roman law. # ''Digesta/Pandectae'': This was the collection of the edicts. # ''Codex'': This contained all the laws of the emperors. # ''Novellae'': This contained all new laws created.

Middle Ages

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. 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. 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.

''Ius Civile''

= Early scholastics (1070–1263)

= The rediscovery of the Digesta from the ''Corpus Iuris Civilis'' led the university of Bologna to start teaching Roman law. 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: * ''Glossae'': translations of the old Roman laws * ''Summae'': summaries * ''Brocardica'': short sentences that made the old laws easier to remember, a sort of mnemonic * ''Quaestio Disputata'' (''sic et non''): a dialectic method of seeking the argument and refute it. Accursius wrote the '' Glossa Ordinaria'' in 1263, ending the early scholastics.

= Late scholastics (1263–1453)

= 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.

Canon Law

= Early Scholastics (1070–1234)

= 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 (19 May) 1918, when a revised '' Code of Canon Law'' (''Codex Iuris Canonici'') promulgated by
Pope Benedict XV Pope Benedict XV (Ecclesiastical Latin, Latin: ''Benedictus XV''; it, Benedetto XV), born Giacomo Paolo Giovanni Battista della Chiesa, name=, group= (; 21 November 185422 January 1922), was head of the Catholic Church from 1914 until his deat ...
on 27 May 1917 obtained legal force.

= Late Scholastics (1234–1453)

= The Decretalists, like the post-glossators for ''Ius Civile'', started to write treatises, comments and advises with the texts.

Ius Commune

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. 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. After the
French Revolution The French Revolution ( ) was a period of radical political and societal change in France that began with the Estates General of 1789 and ended with the formation of the French Consulate in November 1799. Many of its ideas are consid ...
, 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.

Functions of the judiciary in different law systems

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''.

Country-specific functions

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 court A court of appeals, also called a court of appeal, appellate court, appeal court, court of second instance or second instance court, is any court of law that is empowered to hear an appeal of a trial court or other lower tribunal. In much ...
s and then the Supreme Court. State courts, which try 98% of
litigation - A lawsuit is a proceeding by a party or parties against another in the civil court of law. The archaic term "suit in law" is found in only a small number of laws still in effect today. The term "lawsuit" is used in reference to a civil act ...
,American Bar Association (2004)
How the Legal System Works: The Structure of the Court System, State and Federal Courts
. In ''ABA Family Legal Guide''.
may have different names and organization; trial courts may be called "courts of common plea", appellate courts "superior courts" or "commonwealth courts". 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. In
France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...
, 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 China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones ...
, the final authority on the interpretation of the law is the National People's Congress. Other countries such as
Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America South America is a continent entirely in the Western Hemisphere and mostly in the Souther ...
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.

Judicial systems by country


Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the n ...
's process for selecting judges is longer and more stringent than in various countries, like the
United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territor ...
and in
Mexico Mexico ( Spanish: México), officially the United Mexican States, is a country in the southern portion of North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere ...
. 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.


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 11 ministers of the Supreme Court, 32 circuit tribunals and 98 district courts. The Supreme Court of Mexico is located in
Mexico City Mexico City ( es, link=no, Ciudad de México, ; abbr.: CDMX; Nahuatl: ''Altepetl Mexico'') is the capital and largest city of Mexico Mexico ( Spanish: México), officially the United Mexican States, is a country in the southern portion ...
. Supreme Court Judges must be of ages 35 to 65 and hold a law degree during the five years preceding their nomination.

United States

United States Supreme Court justices are appointed by the
President of the United States The president of the United States (POTUS) is the head of state A head of state (or chief of state) is the public persona who officially embodies a state Foakes, pp. 110–11 " he head of statebeing an embodiment of the State ...
and approved by the United States Senate. The Supreme Court justices serve for 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 The United States courts of appeals are the intermediate appellate courts of the United States federal judiciary. The courts of appeals are divided into 11 numbered circuits that cover geographic areas of the United States and hear appeals ...
, and United States district courts. 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. Each state,
district A district is a type of administrative division that, in some countries, is managed by the local government Local government is a generic term for the lowest tiers of public administration within a particular sovereign state. This parti ...
and inhabited territory also has its own court system operating within the legal framework of the respective jurisdiction, responsible for hearing cases regarding state and territorial law. All these jurisdictions also have their own supreme courts (or equivalent) which serve as the highest courts of law within their respective jurisdictions.

See also

* Bench (law) * Supreme court * Political corruption * Judicial independence *
Judicial review Judicial review is a process under which executive, legislative and administrative actions are subject to review by the judiciary. A court with authority for judicial review may invalidate laws, acts and governmental actions that are inco ...
* Rule according to higher law *
Rule of law The rule of law is the political philosophy that all citizens and institutions within a country, state, or community are accountable to the same laws, including lawmakers and leaders. The rule of law is defined in the ''Encyclopedia Britannic ...


Further reading

* Cardozo, Benjamin N. (1998). '' The Nature of the Judicial Process''. New Haven: Yale University Press. * Feinberg, Kenneth, Jack Kress, Gary McDowell, and Warren E. Burger (1986). ''The High Cost and Effect of Litigation'', 3 vols. * Frank, Jerome (1985). ''Law and the Modern Mind''. Birmingham, AL: Legal Classics Library. * Levi, Edward H. (1949) ''An Introduction to Legal Reasoning''. Chicago: University of Chicago Press. * Marshall, Thurgood (2001). ''Thurgood Marshall: His Speeches, Writings, Arguments, Opinions and Reminiscences''. Chicago: Lawrence Hill Books. * McCloskey, Robert G., and Sanford Levinson (2005). ''The American Supreme Court'', 4th ed. Chicago: University of Chicago Press. * Miller, Arthur S. (1985). ''Politics, Democracy and the Supreme Court: Essays on the Future of Constitutional Theory''. Westport, CT: Greenwood Press. * * Tribe, Laurence (1985). ''God Save This Honorable Court: How the Choice of Supreme Court Justices Shapes Our History''. New York: Random House. * Zelermyer, William (1977). ''The Legal System in Operation''. St. Paul, MN: West Publishing.

External links

* * * {{Authority control Separation of powers