Greater London is often referred to as "the City" or "the Square Mile" and it forms the main financial district. Archaically, the urbanised area of London was known as the Metropolis. In common usage, the terms "London" and "Greater London" are usually used interchangeably. Greater London is officially divided for some purposes, with varying definitions, into Inner London and Outer London. For some strategic planning purposes it is divided into five sub-regions. Greater London is under the strategic local governance of the Greater London Authority (GLA). It consists of an elected assembly, the London Assembly, and an executive head, the Mayor of
Flag of the City of London it is hanging down (see below). This flag does not represent Greater London (which does not have its own flag, aside from the banner of the arms of the former Greater London Council), only the historical City of London which covers approximately . All references in this article relate to that city, not Greater London, unless specified. The flag is a banner of arms, derived from the city's coat of arms with the sword symbolising the sword that beheaded Saint Paul who is the patron saint of the city. Saint Paul has featured as a symbol of the city since