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
Economy of London firms, insurance companies and reinsurance markets. London is notable as a centre of international finance where foreign participants in financial markets come to deal with one another. It is also home to the Bank of England, the second oldest central bank in the world, and the European Banking Authority, although the latter is moving to Paris in March 2019 following the Brexit referendum of 2016. Other key institutions are Lloyd's of London for insurance, the Baltic Exchange for shipping. A second financial district has developed at Canary Wharf to the east of the City, which includes the global headquarters of