Royals gather as Trooping the Colour marks Queen's official birthday

The Queen celebrates her official birthday today with the Trooping the Colour parade.

The annual event will see more than 1,000 soldiers taking part in the traditional display of pomp and pageantry.

Royal fans will be hoping to get a glimpse of Princess Charlotte and Prince George on the balcony of Buckingham Palace, where members of the monarchy gather to wave to the crowds in The Mall after the ceremony.

The Queen and Duke of Edinburgh will ride in a vintage carriage from Buckingham Palace, along The Mall to Horse Guards Parade in central London where the event will be staged.

With Philip's recent announcement that he will retire from public duties after the summer, this could be the last time the public see him play such a visible role in the ceremony.

As with previous years, the Duchess of Cambridge, Prince Harry, the Duchess of Cornwall and the Duke of York are expected to take part in the Queen's carriage procession.

The Prince of Wales, who is Colonel of the Welsh Guards, the Princess Royal, Colonel of the Blues and Royals, and the Duke of Cambridge, Colonel of the Irish Guards, will be on horseback.

The procession will be accompanied by a Sovereign's Escort of the Household Cavalry, made up of Life Guards and Blues and Royals, in their silver and gold breastplates and plumed helmets.

The Colour being paraded on Horse Guards this year is the flag of the 1st Battalion Irish Guards.

Four of the five Foot Guards regiments of the Household Division - the Grenadier, Coldstream, Scots and Irish Guards - will march in the parade wearing bearskin hats and red tunics.

The Household Division Bands and Corps of Drums will also take part, as will the King's Troop Royal Horse Artillery who, following the parade, will fire a 41-gun salute in Green Park to mark the Queen's official birthday.

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 30 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 91.