A warm wave of applause greeted the birthday Royal as she arrived, with the Prince of Wales at her right hand, in an open carriage on London's Horse Guards.

There waiting to entertain her were a cast of 7,000, including celebrities, military bands, 1,000 troops, people on carnival floats and in vintage cars, a massed choir, the Royal Philharmonic Orchestra, 100 horses, five camels, bulls, sheep, chickens, winkles - and her own corgis, Rush and Minnie, who joined the parade.

Summer even arrived for the Queen Mother, who is 100 on August 4, to enjoy the pageant in bright sunshine.

At the end of the show, which was scheduled to last one hour but overran by 20 minutes, an emotional Queen Mother thanked everyone for taking part.

She said: "I would just like to say a heartfelt thank you to all those who have come from far and near to take part in this lovely parade.

"It has been a great joy to be here. And the marchers, the children, my regiments, especially the music - the excellent musicians - have been a wonderful joy to hear.

"I do hope you have all enjoyed it as much as I have. It has been a wonderful evening and I would just like to say God bless you all and thank you." But earlier, bomb alerts spread through central London after a device was planted on a railway line near Ealing Broadway station.

Pageant organiser Major John Petrie said the alerts were designed to disrupt the event. Parts of the capital were gridlocked as organisers pressed ahead with morning rehearsals.

The Queen Mother, in pale pink, drove to the parade ground from nearby Clarence House, her London residence, accompanied by her favourite grandson, the heir to the throne.

The two Royals travelled in an open carriage as planned. In the audience of 12,400 were 21 other senior members of the Royal Family, including: the Duke of York with daughters Princess Beatrice and Princess Eugenie, the Princess Royal with son Peter Phillips and husband Commodore Timothy Laurence.

The Queen and Duke of Edinburgh stayed away so as not to upstage the Queen Mother, who took the Royal salute.

Unsurprisingly, the Queen and the Duke were expected to watch the live TV broadcast of the pageant, complete with a flypast by Second World War aircraft and the RAF Red Arrows.

With military precision, the Queen Mother and her attentive grandson arrived exactly on time at 5.06pm to the national anthem.

The Queen Mother took the Royal salute seated in her carriage and was then driven around the parade ground to inspect the massed ranks of servicemen and women, from the army, navy and air force.

With Charles close at hand, she then carefully climbed down from the small carriage and, with two walking sticks, made her way slowly to the Royal dais.

It was billed as the biggest 100th birthday party in the world.

First was a military march past from units associated with the Queen Mother during her long life and including Commonwealth troops from Australia, Canada, New Zealand and South Africa.

Next came the Cavalcade of a Hundred Years, illustrating changing Britain during the Queen Mother's lifetime with vintage vehicles, aircraft, fashion and communications.

There was a special cheer for the Queen Mother's favourite funny man, Sir Norman Wisdom, actresses Wendy Craig and Barbara Windsor, and for wartime songstress Dame Vera Lynn.

Then came a parade by the Queen Mother's charities - about 320 groups with whom she has campaigned over the years, including the Red Cross, St John Ambulance, the Royal British Legion, Mothers' Union and Royal National Lifeboat Institution. The massed choir of singers were from St Paul's Cathedral, Coventry, Dover, Lloyds of London and the City, Christchurch and Magdalen Colleges at Oxford University, and the Royal College of Music. In addition, 25 youngsters from the Royal School of Deaf Children "sang" by sign language.

Some 21 holders of the Victoria Cross and George Cross bravery awards paraded in open Rolls-Royces. Chelsea Pensioners marched past. T

Tere were contributions from the National Trust - starring actress and former model Jerry Hall dressed as the Goddess Flora - gardeners and rose growers, fishermen, dancers from Sadler's Wells, and livery companies with participants in carriages - and on camels.

The Worshipful Company of Grocers, whose coat of arms includes a camel, decided to do something different for the pageant, so they hired camels to ride in the procession.

Winkles - edible sea snails - also made an appearance with 20 representatives of the Winkle Club from Hastings, on the East Sussex coast, which was established as a fundraising charity in 1900 and shares a centenary with the Queen Mother.

Perhaps the Queen Mother's favourites were the tri-service massed band, massed mounted bands, and massed pipes and drums.

Veteran actor Sir John Mills paid tribute to the guest of honour. "Thank you for everything you have meant to the people of this nation and the Commonwealth," he said.

Thirty children, dressed as pieces of cake, then formed a 100th birthday cake before a giant 100th birthday card, signed by all participants, was presented.

One million rose petals were released to rain down on the Queen Mother in her 100th year. Before leaving the parade ground, the birthday Royal was driven around Horse Guards, waving and smiling broadly.