The 86-year-old herself cut a subdued figure as she attended a thanksgiving service at St Paul's Cathedral and a celebratory lunch without Prince Philip, her husband of 64 years who was taken ill with a bladder infection on Monday.

It was one of the few grand state occasions in her life when he has not been present, taking some of the gloss of what is widely seen as a triumphant jubilee that has cemented the queen's popularity.

"Our prayers and thoughts are very much with him this morning," Rowan Williams, the Archbishop of Canterbury and spiritual leader of the Anglican church, said in his sermon.

Millions have attended street parties, watched a spectacular 1,000-vessel pageant on the River Thames in London on Sunday and a concert in front of Buckingham Palace on Monday, all held in honour of Elizabeth II, the only British monarch other than Queen Victoria to have reigned for 60 years.

In a rare move, the queen, who usually only appears on TV screens for a short message on Christmas Day, will deliver a special broadcast be aired at 1700 GMT to thank the nation.

Crowds began massing in huge numbers on the wide Mall avenue towards Buckingham Palace, turning the famous road into a sea of red, white and blue, for the jubilee finale when the royal family will appear on the balcony, with a fly-past by modern and former Royal Air Force aircraft.

POMP AND PAGEANTRY

After the celebrity glitz of the pop concert, Tuesday's events were more typical of the formal displays of ceremony for which British royalty is known across the globe.

Courtiers in an array of ceremonial red and golden tunics and mounted soldiers wearing shining helmets and breastplates dating from centuries past when Britain was an imperial power accompanied a parade through central London.

With Philip absent, the queen led the horse-drawn carriage procession to Buckingham Palace in an open-top 1902 State Landau with heir-to-the-throne Prince Charles and his wife Camilla, while military bands played and a 60-gun salute was fired.

Charles's sons Prince Harry and Prince William with his wife Kate, in an Alexander McQueen dress, followed behind in other carriages.

Earlier Elizabeth - dressed in a fine silk tulle outfit, embroidered with tiny mint green star-shaped flowers embellished with silver thread - had arrived at Paul's Cathedral to shouts of "God save the Queen" from crowds lining the route.

A trumpet fanfare played as the monarch headed into the grand Christopher Wren-designed church, making her way up the aisle past bowing and curtsying members of the congregation.

Commentators said the church service for Elizabeth, who came to the throne aged 25 in 1952, would hold particular poignancy for the queen who as titular head of the Church of England holds her religious role close to her heart.

"We are marking today the anniversary of one historic and very public act of dedication - a dedication that has endured faithfully, calmly and generously through most of the adult lives of most of us here," said Rowan Williams.

"We are marking six decades of living proof that public service is possible and that it is a place where happiness can be found," he told the congregation, which also heard a reading from Prime Minister David Cameron.

Afterwards the royals enjoyed a lavish lunch at Westminster Hall, the oldest part of the Houses of Parliament and the site for the lying-in-state of her mother, the Queen Mother, after her death in 2002.

The guests, including current and former senior politicians, enjoyed a menu featuring salmon from Uist Island north of Scotland and saddle of Welsh Cambrian Mountain lamb, along with an aptly named Jubilee sauce.

SUCCESS AND POPULARITY

The long weekend dedicated to the diamond jubilee has been seen as a success story for the monarchy, their media team and Elizabeth personally, and even typically inclement weather has failed to dampen enthusiasm of many of her subjects.

Polls suggest the crown and the queen herself are more popular than they have been for decades, with one suggesting the hereditary monarch was more in touch with her people than Cameron and his ministers.

Meanwhile the younger generation of royals, especially William, Harry and Kate, have become the darlings of the British press, once notoriously hostile to the monarchy as it threatened to implode in the 1990s following marital infidelities and the death of Charles's hugely popular first wife, Princess Diana.

Republicans have been vocal in their opposition during the jubilee but have drawn few obvious signs of public backing, although they hope that apathy to the royals felt by some could turn to hostility when the queen is gone and the less popular Charles becomes king.

If nothing else, commentators said the royals had once again provided Britons, suffering through financial hardships, deep public spending cuts and rising unemployment, an excuse to forget their woes and enjoy a party.

"With the economy and one thing or another, this has just been the most fantastic celebration," said designer Sheree Charalampous, 53, who had made her own crown, strung with pearls, pictures of corgis and a portrait of the queen.

"I really think the monarchy is now back in favour again, which is wonderful. Nobody does this sort of thing like us. It has been an amazing four days, just fantastic."

(Additional reporting by Peter Griffiths; Editing by Paul Casciato)

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