Prince William in first Trooping the Colour parade

The Duke of Cambridge has helped the Queen celebrate her official birthday by taking part in his first Trooping the Colour parade.

Newly married Prince William rode on horseback for the spectacle at Horse Guards in London as his wife looked on.

The Duchess of Cambridge rode in a horsedrawn carriage with Prince Harry and the Duchess of Cornwall.

Later, members of the Royal Family gathered on the balcony at Buckingham Palace to watch a flypast by the RAF.

The ceremony marked the 85th birthday of the Sovereign and came a day after the Duke of Edinburgh's 90th birthday.

Traditional flypast

Prince William, dressed in the red uniform of the Irish Guards he wore on his wedding day six weeks ago, took part in the parade as the regiment's honorary colonel.

Sporting a traditional bearskin hat, he rode the Household Division charger Wellesley in the ceremony dating back to 1748.

Alongside him, also on horseback, were the Prince of Wales - Colonel of the Welsh Guards, the Princess Royal - Colonel of the Household Cavalry's Blues and Royals and Colonel of the Scots Guards, the Duke of Kent.

The Queen, who actually turned 85 on 21 April, arrived in a carriage with the Duke of Edinburgh, who was dressed as Colonel of the Grenadier Guards.

They stood side by side as the ceremonial flag was paraded past her, followed by Guardsmen in both slow and quick time whilst the Massed Bands played.

The colour trooped this year was that of the 1st Battalion Scots Guards.

Prince William's wife, Catherine, was dressed in an ivory jacket and black hat, and had a tartan quilt over her knees, as did Camilla.

She and the other royals were cheered by thousands of spectators as they headed to the parade ground.

Others in attendance were the Duke of York, Earl and Countess of Wessex, their seven-year-old daughter Lady Louise Mountbatten-Windsor, Princess Eugenie and Prime Minister David Cameron.

After a gun salute for the Queen, performed by The Kings Troop Royal Horse Artillery, the duchess appeared on the Buckingham Palace balcony with members of her new family.

The royals then watched some 25 aircraft take part in the traditional RAF flypast, including the Battle of Britain Memorial Flight's Spitfire, Hurricane and Lancaster, modern-day Typhoon fighters, and the Red Arrows aerobatics display team.

After the Duchess of Cambridge's first public engagement with her new title on Thursday - a lavish dinner with charitable giving and considerable wealth on display - this was more familiar royal territory, says BBC royal correspondent Peter Hunt.

He says the duchess watched her husband embrace yet another aspect of his destiny - a ceremonial occasion which one day, as things stand, will be held in his honour.

On the Duke of Edinburgh's 90th birthday, the Queen conferred on him the title of Lord High Admiral of the Navy.

Prince Philip hosted an event for the Royal National Institute for Deaf People at Buckingham Palace during which guests gave the duke a spontaneous rendition of Happy Birthday.