Various.

The Corporation of London is the local authority for the City of London or Square Mile, the financial and commercial centre at the heart of the metropolitan area. With its roots in medieval times, it is probably the oldest local authority in the United Kingdom and has an unusually wide range of responsibilities reflecting both its ancient role as a municipality and its modern-day role as the equivalent of a London Borough. The Corporation of London is also unique in local government as it has no charter of incorporation nor any specific date of establishment: it has evolved organically from earlier bodies. Most other councils in the United Kingdom were either created or substantially reformed in the 19th century or later.

Where "Corporation" is used in modern legislation such as City of London (Various Powers) Acts, its meaning is defined as "the Mayor and Commonalty and Citizens of the City of London". This latter title is one of the styles used in the charter dated 20 Sep 1608, which also lists the following titles or styles: Mayor and Aldermen of the City of London; Mayor, Citizens and Commonalty of the City of London; Mayor and Commonalty of the City of London; Citizens of the City of London; Barons of London; Barons of the City of London and indeed "any other name whatsoever, by reason or force of any letters patent, charters, or confirmations of any of our progenitors, Kings of England, which in any time or times had reasonably used or exercised". In 1690 an Act of Parliament confirming all the privileges of the Corporation of London declared that the Mayor and Commonalty and Citizens of the City of London should "remain continue, and be, and prescribe to be a body corporate and politick, in re, facto et nomine".

Another unusual feature of the Corporation of London is its ability to alter or amend its constitution when it benefits the Corporation of London and City of London to do so, under charters of Edward III (1341) and Richard II (1377 and 1383). This power is exercised by means of Acts of Common Council. Such Acts of the Corporation of London are authenticated by the City or Common Seal. Although the legal title of the Corporation of London remains 'the Mayor and Commonalty and Citizens of the City of London', statutory powers are usually conferred on the Court of Common Council, under the designation of 'the Mayor, Aldermen and Commons of the City of London in Common Council assembled'.

In 1682 - 1683 the King's Bench issued a writ of Quo Warranto against the City of London which led to the Charter of the City being forfeited and the Corporation of London being dissolved, reducing the city to the legal status of a small village. Quo Warranto writs had often been used to regulate liberties and franchises, such as the right to hold a fair or a market. It was claimed that the City of London had breached its Charter by allowing the collection of tolls at market and by publishing a seditious petition against the King and Government - these abuses of the ancient liberties of the City were enough to justify issuing the writ. The overall aim of the King, Charles II, was to control the personnel and the government of the Corporation of London. After the Charter was forfeited the King issued a new one giving him the right to appoint and remove officers, including the Mayor, Sheriffs, Recorder, Common Sergeant, Justices of the Peace and Coroner, thus allowing him direct control over the government of the City. Between 1683 and 1688 the City of London was governed by a Royal Commission. In October 1688 King James II issued a Proclamation restoring the City Liberties as fully as before the Quo Warranto judgement. In 1690 a Special Committee of the House of Commons declared the judgement illegal and an Act of Parliament was passed restoring the City to its ancient rights, enacting that the City might prescribe to be a corporation and declaring that the Charter of the City of London should never be forfeited for any cause whatsoever.