The Inns of Court in London are the professional associations for barristers in England and Wales. There are four Inns of Court: Gray's Inn, Lincoln's Inn, Inner Temple and Middle Temple.
All barristers must belong to one of them. They have supervisory and disciplinary functions over their members. The Inns also provide libraries, dining facilities and professional accommodation. Each also has a church or chapel attached to it and is a self-contained precinct where barristers traditionally train and practise, although growth in the legal profession, together with a desire to practise from more modern accommodations and buildings with lower rents, caused many barristers' chambers to move outside the precincts of the Inns of Court in the late 20th century.
During the 12th and early 13th centuries, law was taught in the City of London, primarily by the clergy. But a papal bull in 1218 prohibited the clergy from practising in the secular courts (where the English common law system operated, as opposed to the Roman civil law functioning in the Church's ecclesiastical courts). As a result, law began to be practised and taught by laymen instead of by clerics. To protect their schools from competition, first Henry II ( 1154 - 1189) and later Henry III ( 1216 - 1272) issued proclamations prohibiting the teaching of the civil law within the City of London. The common-law lawyers worked in guilds of law, modelled on trade guilds, which in time became the Inns of Court.
In the earliest centuries of their existence, beginning with the 14th century, the Inns were any of a sizeable number of buildings or precincts where lawyers traditionally lodged, trained and carried on their profession. Over the centuries, the four Inns of Court became where barristers were trained, while the more numerous Inns of Chancery – which were initially affiliated to the Inns of Court – became associated with the training of solicitors in the Elizabethan era.