Horse Guards is a large grade I listed building in the Palladian style between Whitehall and Horse Guards Parade in London, England. It was built between 1751 and 1753 by John Vardy to a design by William Kent. The building was constructed on the site of the Guard House of the old Whitehall Palace, which had been destroyed by fire in 1698. The palace's tiltyard became the exercise ground of Horse Guards Parade, located behind the Horse Guards building.
Horse Guards Road runs north-south on the western boundary of the parade ground, while Horse Guards Avenue runs east from Whitehall on other side of the building, to Victoria Embankment.
The building was the headquarters of the British Army's general staff and served as the offices of the Commander-in-Chief of the British Army until the post was abolished in 1904. Horse Guards subsequently became the headquarters of two major Army commands: the London District and the Household Cavalry. The building is the formal entrance to St. James's Palace via St. James's Park (though this is now entirely symbolic). Only the monarch is allowed to drive through its central archway, or those given a pass (formerly made of ivory).
Horse Guards is normally guarded by troopers of the Household Cavalry, both mounted and on foot; visiting the horses is popular with tourists. Two mounted cavalry troopers are posted outside daily from 10 am to 4 pm, and are relieved every hour. Also two Troopers are posted from 10 am till 8 pm and are relieved every two hours. There is the changing of the guard at 11 am everyday but on Sundays is brought forward to 10 am. Also there is the inspection of the guard that takes place at 4 pm everyday, which dates back to when Queen Victoria came through the entrance but didn't find anybody there because they were drunk on ale. As a result she ordered, the Household Cavalry to parade at 4 pm every day for 100 years just to make sure it didn't happen again. It has been over 30 years since the hundred years order ended but the Household Cavalry still carry out this tradition. There are usually guided tours of the building on London Open House weekend, which takes place in September. At the Royal Wedding of Kate and William, Horse Guards had a youth enclosure containing Guides, Scouts and other youth groups outside it to watch the procession.