A curia, plural curiae, is an assembly, council, or court, in which public, official, or religious issues are discussed and decisions made. In ancient Rome, the entire populace was divided into thirty curiae, which met in order to confirm the election of magistrates, witness the installation of priests, the making of wills, and adoptions. Lesser curiae existed for other purposes. The word curia also came to be applied to meeting places where various assemblies gathered, especially the meeting house of the senate. Similar institutions existed in other towns and cities of Italy. In medieval times, a king's council was frequently referred to as a curia. Today, the most famous curia is the Curia of the Roman Catholic Church which assists the Roman Pontiff in conducting the business of the Church.
The word curia is thought to derive from Old Latin coviria, meaning "a gathering of men" (co-, "together" =vir, "man"). In this sense, any assembly, public or private, could be called a curia. In addition to the Roman curiae, voting assemblies known as curiae existed in other towns of Latium, and similar institutions existed in other parts of Italy. During the republic, local curiae were established in Italian and provincial municipia and coloniae. In imperial times, local magistrates were often elected by municipal senates, which also came to be known as curiae. By extension, the word curia came to mean not just a gathering, but also the place where an assembly would gather, such as a meeting house.
The Comitia Curiata
The most important curiae at Rome were the thirty that together made up the comitia curiata. Traditionally ascribed to the kings, each of the three tribes established by Romulus, the Ramnes, Tities, and Luceres, was divided into ten curiae. In theory, each gens (family, clan) belonged to a particular curia, although whether this was strictly observed throughout Roman history is uncertain.
Each curia had a distinct name, said to have been derived from the names of some of the Sabine women carried off by the Romans in the time of Romulus. However, some of the curiae evidently derived their names from particular districts or eponymous heroes. The curiae were probably established geographically, representing specific neighborhoods in Rome, for which reason curia is sometimes translated as "ward". Only a few of the names of the thirty curiae have been preserved, including Calabra, Faucia, Foriensis, Rapta, Veliensis, Tifata, and Titia.
The assertion that the plebeians were not members of the curiae, or that only the dependents (clients) of the patricians were admitted, and not entitled to vote, is expressly contradicted by Dionysius  This argument is also refuted by Mommsen.
Each curia had its own peculiar sacra, in which its members, known as curiales, worshipped the gods of the state and other deities specific to the curia, with their own rites and ceremonies. Each curia had a meeting site and place of worship, named after the curia. Originally this may have consisted of a simple altar, then a sacellum, and finally a meeting house where the curiales could discuss various matters.
The curia was presided over by a curio (plural, curiones), who was always at least fifty years old, and was elected for life. The curio undertook the religious affairs of the curia. He was assisted by another priest, known as the flamen curialis. When the thirty curiae gathered to make up the comitia curiata, they were presided over by a curio maximus, who until 209 BC was always a patrician. Originally, the curio maximus was probably elected by the curiones, but in later times by the people themselves. Each curia was attended by one Lictor; an assembly of the comitia curiata was attended by thirty lictors.
The comitia curiata voted to confirm the election of magistrates by passing a law called the lex curiata de imperio. It also witnessed the installation of priests, and adoptions, and the making of wills. The Pontifex Maximus may have presided over these ceremonies. The assembly probably possessed much greater authority before the establishment of the comitia centuriata, which gradually assumed many of the curiate assembly's original functions.
The Senate House
From the time of the kings, the meeting-house of the Roman senate was known as the curia. The original meeting place was said to have been a temple built on the spot where the Romans and Sabines laid down their arms during the time of Romulus (traditionally reigned 753–717 BC). The institution of the senate was always ascribed to Romulus; although the first senate was said to comprise one hundred members, the earliest number which can be called certain is three hundred, probably connected with the three tribes and thirty curiae also attributed to Romulus.
The Curia Hostilia
After the original temple was destroyed by fire, it was replaced by a new meeting house by Tullus Hostilius, the third King of Rome (traditionally reigned 673–642 BC). The Curia Hostilia stood on the north end of the comitium, where the comitia curiata and other Roman assemblies met, and was oriented along the four cardinal points. After more than five hundred years of service, the building was restored and enlarged by the dictator Lucius Cornelius Sulla in 80 BC. Sulla had doubled the senate's membership from three hundred to six hundred, necessitating a larger building, which retained the original orientation of the Curia Hostilia, but extended further south into the comitium. In 52 BC, following the murder of Publius Clodius Pulcher, his clientes set fire to the senate house, which was rebuilt by Faustus Cornelius Sulla, son of the dictator. Following this reconstruction, the building came to be called the Curia Cornelia.
The Curia Julia
A generation after Sulla enlarged the senate from three hundred members to six hundred, Julius Caesar increased its membership to nine hundred, necessitating the construction of a larger meeting house. The Curia Cornelia was demolished, and shortly before his death in 44 BC, Caesar began the construction of a new building, which became known as the Curia Julia. This structure covered most of the comitium, and abandoned the original orientation of the previous curiae, pointing slightly northwest. The building featured a large central hall with a daïs for magistrates, and marble benches on one side. There was also a record office on one side. The building was completed by Caesar's nephew, Octavian, the future emperor Augustus, in 29 BC, although he reduced the senate itself to its former number of six hundred.
In AD 94, the Curia Julia was rebuilt along Caesar's original plan by the emperor Domitian, who also restored the former orientation of the Curia Hostilia. The building was damaged by fire during the reign of Carinus in 283, and again restored under his successor, Diocletian. The Roman Senate is last mentioned in AD 600. In 630, Pope Honorius I transformed the senate house into the church of Sant'Adriano al Foro, preserving the structure at its full height. In 1923, the church and an adjacent convent were purchased by the Italian government. The building was further restored from 1935 to 1937, removing various medieval additions, to reveal the original Roman architecture.
In the Roman Empire the curia (ordo, boule) was the town council, the governing body of a city and the hallmark of city rank. It was a co-optive body, whose members, the Decurions, sat for life. Its numbers vary greatly according to the size of the city. In the Western Empire, 100 seems to have been a common number, but in the East 500 was customary on the model of the Athenian Boule. However by the fourth century, curial duties had become onerous and it was difficult to fill all the posts, and often candidates had to be nominated. Constantine exempted Christians from their curial duties which led to many rich pagans claiming to be priests in order to escape the duties. 
In medieval times, a king's court was frequently known as the curia regis, consisting of the king's chief magnates and councilors. In England, the curia regis gradually developed into Parliament. In France, the curia regis or Conseil du Roi developed in the twelfth century, with the term gradually becoming applied to a judicial body, and falling out of use by the fourteenth century.
Roman Catholic Church
The term curia may refer to separate electoral colleges in a system of reserved political positions (reserved seats), e.g. during the British mandate of Palestine at the third election (1931) of the Asefat HaNivharim there were three curiae, for the Ashkenazi Jews, the Sephardi Jews and for the Yemeni Jews.
- Code of Canon Law, can. 360
- Webster's Third New International Dictionary (1966).
- Oxford Classical Dictionary, 2nd Ed. (1970).
- Harper's Dictionary of Classical Literature and Antiquities, Second Edition, Harry Thurston Peck, Editor (1897)
- Dionysius of Halicarnassus, Romaike Archaiologia iv. 12, 20.
- Christian Matthias Theodor Mommsen, Römische Forschungen.
- Sextus Pompeius Festus, epitome of Marcus Verrius Flaccus, De Verborum Significatu.
- Marcus Tullius Cicero, De Lege Agraria contra Rullum
- "A H M Jones, The Later Roman Empire, p 724"
- Code of Canon Law, can. 360
- Fannie Fern Andrews, The Holy Land under mandate, Boston and New York, Houghton Mifflin Company - The Riverside Press Cambridge, 1931, 2 vol. (ch. XIV - Building a Jewish corporate life, vol. II, 1-32)
- Moshe Burstein, Self-government of the Jews in Palestine since 1900, Tel Aviv, Hapoel Hatzair, 1934
- ESCO Foundation for Palestine, Inc., Palestine. A study of Jewish, Arab and British policies, New Haven, Yale University Press, 1947, 2 vol. (The growth and organization of the Jewish community, vol.II, 404-414)
- Jacob C. Hurewitz, The struggle for Palestine, New York, Norton and Company, 1950 (ch. 3 - The political structure of the Yishuv, 38-50)