Trooping the Colour parade marks the Queen's official birthday
The Queen will celebrate her official birthday today with the traditional Trooping the Colour parade.
The annual event sees more than 1,000 soldiers taking part in the traditional display of pomp and pageantry on Horse Guards Parade in central London.
The Duchess of Cambridge will join other members of the Royal Family at the spectacle - her first public appearance since she left hospital after giving birth to daughter Princess Charlotte on 2 May.
And there is speculation Prince George may join his parents on Buckingham Palace's balcony where members of the monarchy gather to wave to the crowds in The Mall, following the military display, and watch the traditional fly-past of aircraft.
After the Queen takes the salute on Horse Guards, the Royal Family will head back to Buckingham Palace and gather on the balcony to watch the RAF fly-past.
Among the 31 aircraft taking part are Spitfires and Hurricanes, made famous in the Battle of Britain 75 years ago, and also modern jets like the multi-role Typhoon fighter while the Red Arrows will be the finale.
Trooping the Colour originated from traditional preparations for battle.Colours, or flags, were carried, or ''trooped'', down the rank so that they could be seen and recognised by the soldiers.
In the 18th century, guards from the royal palaces assembled daily on Horse Guards to ''troop the colours'', and in 1748 it was announced that the parade would also mark the Sovereign's official birthday.
The Queen's actual birthday was on April 21, when she turned 89.