To mark the Diamond Jubilee celebrations of 2012, this year’s British Military Tournament will cover the "life and times" of Queen Elizabeth II, starting with the events of 1926 (the year the Queen was born) and finishing with the current-day military engagement in Afghanistan.
The event is described as the largest display of military theatre anywhere in the world and will include:
More than 600 participants (including active servicemen) and 150 horses.
The bands of the Royal Marines, the Household Cavalry, the Royal Artillery and the Royal Air Force.
The horses of the Household Cavalry competing with the motorcycles of the Royal Signals’ White Helmets over an obstacle course which includes jumps and flaming hoops.
A battle re-enactment featuring the Royal Logistic Corps in a dramatic bomb disposal in Afghanistan.
The largest massed bagpipe band seen at Earls Court since the Second World War.
While the rest of the capital was sleeping, hundreds of soldiers rode on horseback through the streets of London to rehearse the State Procession for the Queen's Diamond Jubilee.
Members of The Household Cavalry Mounted Regiment rode at dawn from the Palace of Westminster along Whitehall to Trafalgar Square, then through Admiralty Arch and along the Mall to Buckingham Palace.
The route was lined with personnel from the Royal Navy and Royal Marines, Foot Guards and Massed Bands of the Household Division, the Princess of Wales's Royal Regiment and the Queen's Colour Squadron of the Royal Air Force. In total, some 2,000 servicemen and women took part in the rehearsal.
Thousands of flag-waving well-wishers are expected to turn out for Tuesday's spectacle.
More than 2,500 troops - sailors, soldiers and Royal Air Force personnel from nearly all areas of the Armed Forces - will parade before the Queen and the Duke of Edinburgh through Windsor today. They will be joined by a tri-Service Guard of Honour for Her Majesty, and six military bands.