Trooping the Colour is kicking off the first of four days of celebrations for the Queen's Platinum Jubilee.
The event, which is the Queen's official birthday parade, is a military spectacle, involving more than 1,500 officers and soldiers and 350 horses from the Household Division.
It sees members of the Royal Family travelling in horse-drawn carriages from Buckingham Palace to Horse Guards Parade to watch the extravaganza before travelling back again.