The first Horse Guards building was commissioned by King Charles II in 1663,[1] on the site of a cavalry stables which had been built on the tiltyard of the Palace of Whitehall during the Commonwealth.

Having to reuse the same plot of land, Kent managed to retain essentially the same plan as the original building while doubling the interior space.

The Household Cavalry moved into the northern wing of the uncompleted building in 1755; at that time, there was stabling for 62 horses compared to 17 today.

Originally, the two wings were connected to the central block by single storey ranges; in 1803-5 a further two floors were added to these, giving the building its present appearance.

[5] At the annual Trooping the Colour ceremony in June, members of the Royal Family who are not participants watch the parade from the windows of Wellington's office over the archway.

Originally made by Thwaites in 1756, the clock was rebuilt in 1815–16 by Benjamin Lewis Vulliamy, the clockmaker to King George III.

A dark stain above the Roman number two on the clock face is supposed to mark the time of the execution of King Charles I in 1649, which took place in the roadway outside Horse Guards.

Exhibits explain the training and history of the regiment and include ceremonial uniforms, regalia, royal standards, awards, musical instruments, horse furniture and silverware by Fabergé.

This proclamation and punishment officially expired in 1994, but Queen Elizabeth II chose to continue the inspection out of respect for tradition.

The guard is usually provided by the Household Cavalry Mounted Regiment, which consists of a squadron from each of the Household Cavalry regiments; the Life Guards who wear red tunics and white helmet-plumes, and the Blues and Royals who wear blue tunics and red plumes.