Why does the Queen have two birthdays?

The Queen was actually born on 21 April, but it has long been customary to celebrate the Sovereign's birthday on a day during the summer. Since 1805 the Sovereign's 'official' birthday has been marked by the Trooping the Colour ceremony, normally held on the second Saturday in June.

This is a ceremony which originated when it was essential for soldiers to recognise the flag or 'Colour' of their regiment so that they could follow it into battle. Each year one of the five regiments of the foot guards (Grenadiers, Cold stream Guards, Scots, Irish and Welsh Guards) take turns to display their Colour in the ceremony.

The ceremony begins with the Queen leaving Buckingham Palace escorted by the Household Cavalry. She rides down The Mall to Horse Guards Parade and inspects the 500 guardsmen.

The Colour is trooped by being carried along the ranks of guardsmen, and the Colour party then leads the guards on a march past the Queen, accompanied by the massed bands of the foot guards.

No particular annual ceremony is held on the Queen's true birthday, although the Union Flag is flown on public buildings and the national anthem is sung.