The City of London, also known as the Square Mile, is the financial district and historic centre of London. Despite its name, the City of London is actually only a tiny part of the whole of London, and is dwarfed by the much larger London metropolitan area. It’s known for its high-rise buildings, financial services sector and rich history stretching back to Roman times. Some of its most famous landmarks include the Tower of London, St. Paul's Cathedral and the iconic 'Gherkin' skyscraper.

The City of London is unique in that it has its own local authority, separate from the Greater London Authority that governs the rest of the metropolitan area. In terms of population, it's one of the smallest cities in the UK – at the 2011 Census, it had a permanent population of only 7,375, but around 300,000 people commute into the area every day for work. The City of London is a major global financial hub, hosting the London Stock Exchange, Lloyd's of London and the headquarters of numerous banks and insurance companies. It’s also home to some of the most iconic buildings in London, including the Gherkin, the Walkie-Talkie and the Cheese Grater. The City of London is also home to several historic sites including the Tower of London, Monument to the Great Fire of London and the ancient London Wall.

The City of London has its own local authority, the City of London Corporation, which is separate to the Greater London Authority that governs the rest of London. The Corporation is responsible for providing local services, such as planning, schools and social services. The Corporation also has responsibilities and ownerships beyond the City's boundaries, including open spaces like Hampstead Heath and Epping Forest, and it also provides the police force covering the City of London, separate from the Metropolitan Police Service which covers the rest of Greater London.

The City of London is a major global financial hub, hosting the London Stock Exchange, Lloyd's of London and the headquarters of numerous banks and insurance companies. It has a highly developed and sophisticated financial services industry and is often referred to as the financial capital of the world. The City contributes significantly to the overall economy of London and the UK. While the financial sector is the dominant industry in the City of London, it also has a significant legal sector, with many law firms headquartered here.

The infrastructure of the City of London is designed to support a large daily population of commuters. Major infrastructure includes the Bank of England, the Stock Exchange and Lloyd's of London. In addition, the City of London is served by several major roads and numerous rail and tube stations. The City has a dedicated police force, the City of London Police, which is separate from the Metropolitan Police Service which covers the rest of Greater London. Despite its relatively small size, the City has a large concentration of tall buildings and skyscrapers.