If there's one event that sums up the pomp and pageantry which Britain is renowned for, it's the ceremony of Trooping the Colour each June, when the Household Division parades in London in front of Queen Elizabeth to mark her official birthday. More than 1,400 officers and men from the guards regiments, resplendent in bearskins and scarlet tunics, march to the stirring tunes, played by 400 musicians from 10 bands and corps of drums, from Buckingham Palace along The Mall to Horse Guards Parade and back again, to the delight of thousands of spectators. Precisely as the clock on the Horse Guards building strikes 11, the royal procession arrives and the queen takes the royal salute. The parade begins with an inspection, as the queen rides slowly in her carriage down the ranks of the foot guards and then past the Household Cavalry. After ceremonial marchpasts and the actual trooping of the colour - when the regimental flag is formally carried through the ranks - the city echoes to the thunder of a 41-gun royal salute fired by the King's Troop Royal Horse Artillery in nearby Green Park, which is answered by a 62-gun royal salute fired by the Honourable Artillery Company at the Tower of London. By this stage, the royal family has gathered on the balcony of Buckingham Palace to watch a flypast by the Royal Air Force. In 2006, the queen's 80th birthday was marked by the largest flypast consisting of 40 aircraft led by the Battle of Britain Memorial Flight. The custom of Trooping the Colour dates back to the reign of CharlesII in the 17th century when the colours of a regiment were used as a rallying point in battle, and were trooped in front of the soldiers every day to make sure that every man was familiar with them. In 1805, the parade was held for the first time to celebrate the sovereign's birthday, and has been every year since, with the exception of 1955 when it was cancelled due to a rail strike. Each of the guards regiments has its own colour, and the honour of trooping is taken in strict rotation between the Coldstream, Grenadier, Scots, Welsh and Irish guards. This year, it will be trooped by the 1st Battalion the Welsh Guards. Trooping the Colour is the embodiment of military precision, with the parade responding with perfect synchronism to the 113 separate commands. Sometimes jocularly called wooden tops or chocolate warriors by their comrades in other regiments in the British Army, every one of the guardsmen on parade is a trained soldier, and could have recently returned from operations in Iraq or another theatre of war - a reminder that Trooping the Colour is no mere military musical extravaganza.