The Lord Mayor's Show is one of the best-known annual events in London as well as one of the longest-established, dating back to the 16th century. The 'Lord Mayor' after whom the show is named is the Lord Mayor of the City of London, a city and ceremonial county within Greater London and the historic centre of the wider metropolis. The City is also London's main modern financial district, widely known informally as 'the Square Mile'.
A new lord mayor is appointed every year and the public parade that takes place as his or her inauguration ceremony reflects that this was once one of the most prominent offices in England. The position of Lord Mayor has a role within the City and is entirely distinct from the position of Mayor of London (a role which has existed only since 2000), namely the elected head of the Greater London Authority, currently Sadiq Khan.
The Lord Mayor's Show is centred on a street parade which in its modern form is a light-hearted combination of traditional British pageantry and elements of carnival. On the day after being sworn in, the Lord Mayor and several others participate in a procession from the Guildhall, via Mansion House and St Paul's Cathedral, in the heart of the City of London, to the Royal Courts of Justice on the edge of the City of Westminster, where the new Lord Mayor swears allegiance to the Crown. Until 1882 the procession went to Westminster Hall.
The office of Lord Mayor dates from 1189 and it was a requirement of the charter establishing it that the mayor travelled to the royal enclave at Westminster to present himself to the monarch's representatives, the senior judges as Barons of the Exchequer to take an oath of loyalty to the Sovereign upon beginning his term. The event is officially listed in the City's Civic Calendar as 'The Procession to the Royal Courts of Justice and Presentation of the Lord Mayor to the Chief Justices'; when the Royal Courts moved from Westminster to the Strand location in 1882 the route was shortened. Originally this journey was mostly made by barge on the River Thames, the usual method of transport for this route in those days. Pageantry and display gradually grew around the trip, comparable to the far less frequent Royal Entry parades that usually followed a coronation or royal wedding, and by the 16th century the "show" was firmly established as a major entertainment for Londoners.