Horse Guards Parade is a large parade ground off Whitehall in central London, at grid reference. It is the site of the annual ceremonies of Trooping the Colour, which commemorates the monarch's official birthday, and Beating Retreat.HistoryHorse Guards Parade was formerly the site of the Palace of Whitehall's tiltyard, where tournaments (including jousting) were held in the time of Henry VIII. It was also the scene of annual celebrations of the birthday of Queen Elizabeth I. The area has been used for a variety of reviews, parades and other ceremonies since the 17th century.It was once the Headquarters of the British Army. The Duke of Wellington was based in Horse Guards when he was Commander-in-Chief of the British Army. The current General Officer Commanding London District still occupies the same office and uses the same desk. Wellington also had living quarters within the building, which today are used as offices.Car parkFor much of the late 20th century, Horse Guards Parade was used as a car park for senior civil servants; about 500 were granted the privilege, which was known as the 'Great Perk'. The PIRA's mortar attack on 10 Downing Street on 7 February 1991, which was carried out from a vehicle parked in Horse Guards Avenue near to Horse Guards Parade, although producing no casualties, led to concern about security. In April 1993 the Royal Parks Review Group, headed by Dame Jennifer Jenkins, Lady Jenkins of Hillhead, recommended that Horse Guards Parade should be restored for public use, and linked to St James's Park by closing Horse Guards Road. The proposal was taken up by the Department of National Heritage but then resisted by senior Cabinet members, apparently under pressure from the civil servants who were to lose their parking places.