One of Britain's most popular and spectacular occasions, this celebration of the monarch's official birthday has been held since the mid-1700s. Tens of thousands of people attend the actual event and millions more watch on television.

This morning, 17 cameras will capture all the pomp and ceremony as the Second Battalion Grenadier Guards, formed in 1656, troop their Queen's Colour for the last time before going into "suspended animation" as a result of Government defence cuts. Julian Tutt describes the scene as Her Majesty the Queen - accompanied by the Duke of Edinburgh, the Prince of Wales, the Duke of Kent and the Grand Duke of Luxembourg - takes the salute.

But it is not simply a colourful pageant. Many people do not realise that the guardsmen who take part in today's ceremony are all trained soldiers and many have been on tours of duty in hot spots such as Bosnia and Northern Ireland.