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
Central London However, districts at the outer edge of this subregion such as Streatham and Dulwich are not generally considered as Central London. The 1901 census defined Central London as the City of London and the metropolitan boroughs of Bermondsey, Bethnal Green, Finsbury, Holborn, Shoreditch, Southwark, Stepney, St Marylebone and Westminster. During the Herbert Commission and the subsequent passage of the London Government Bill, three unsuccessful attempts were made to define an area that would form a central London borough. The first two were detailed in the 1959 Memorandum of Evidence of the Greater London Group of the London School of Economics.