Britain's royal family crowded onto the balcony of Buckingham Palace in London Saturday to celebrate Queen Elizabeth II's 88th birthday.

Some 32 members of the family joined the monarch to watch a military fly over as part of her official birthday celebrations.

However, baby Prince George, whose first birthday is on July 22, was not among them, his parents Prince William and Catherine leaving him to wait a little longer for his first palace balcony appearance.

Earlier, on the Horse Guards Parade ground, senior royals watched the Trooping the Color event, a lively ceremony that offers an annual dose of traditional British pageantry with soldiers in scarlet tunics and black bearskin hats marching in formation.

The parade, a hangover from preparations for battle when colors or flags were "trooped" down the rank so soldiers could recognize them, marks the queen's official birthday.

Her actual birthday is on April 21 but traditionally the monarch has another in the summer months because the weather is usually better for open-air celebrations.

Queen Elizabeth and her 93-year-old husband Prince Philip, who wore a bearskin hat, travelled to and from the ceremony in an open carriage, despite a light drizzle.

Their grandson William, his father Prince Charles, the heir to the throne, and the queen's daughter Princess Anne rode to the parade on horseback in full military uniform.

Catherine rode in an open carriage with William's brother Prince Harry and the princes' stepmother, Charles's wife Camilla.

After the parade, the royals appeared on the palace balcony for the flypast, which saw modern Typhoon and Tornado fighter jets roar above the crowds.

Britain's last remaining airworthy World War II Lancaster bomber, which last week flew over the French coast as part of the 70th anniversary of the D-Day landings, took part, flanked by two Spitfire fighters from the conflict.

The Red Arrows, the Royal Air Force's aerobatics team, then left trails of red, white and blue smoke in the sky to round off the celebrations.

As a smiling Queen Elizabeth waved goodbye to the crowds, Prince Philip, in jovial spirits, was animatedly chatting to Harry.

The monarch's no-nonsense husband turned 93 on Tuesday with a typical lack of fuss. Guests at a palace summer garden party were told to avoid wishing him a happy birthday.

New Zealander Samantha Webster gave him a woolly scarf as a present but the prince then joked that he didn't want to carry it about.

"He made us laugh when he said, 'Could you hand it to someone. I don't want to lug it around the garden!'," she said.