LONDON VAUXHALL DEALERS

Pealing bells greeted the flotilla as the queen's gilded royal barge sailed alongside a colourful and eclectic array of boats from leisure cruisers and yachts to a Hawaiian war canoe and Venetian gondolas.

Typically inclement British weather failed to dampen enthusiasm, with hundreds of thousands of onlookers, waving "Union Jack" flags, massed on the riverbanks to catch a glimpse of the procession along the seven mile (11 km route).

The queen, wearing a silver and white dress with a matching coat, smiled broadly and waved to the crowds from the royal barge, "The Spirit of Chartwell", alongside her 90-year-old husband Prince Philip.

They were accompanied on the barge by heir-to-the-throne Prince Charles, his eldest son Prince William and new wife Kate, a global fashion trendsetter who wore a vivid red Alexander McQueen dress and matching hat.

Up and down the country, organisers said millions of people attended diamond jubilee street parties in honour of the 86-year-old sovereign, the only British monarch after Queen Victoria to have sat on the throne for 60 years.

"We're English, we know what the weather is like. We really don't care if we get wet you know - it's the jubilee, it's the queen, so it's nice to come up and celebrate it," said Jackie, a 39-year-old sales consultant who travelled across southern England to watch the Thames pageant.

From New Zealand Maoris who paddled their canoe wearing traditional cloaks to sailors and people dressed as pirates, the flotilla boasted a colourful array of participants from every corner of the planet.

There were even vessels from the 1940 evacuation of British and Allied troops from Dunkirk in northern France - a famous rescue performed by crafts of all shapes and sizes and a celebrated piece of British history.

Organisers said Sunday's river pageant, reminiscent of a Canaletto canvas from the 18th century, was the largest of its kind since a similar spectacle was held for King Charles II and his consort Catherine of Braganza in 1662.

CHURCHILL AND EISENHOWER

Other craft included Motor Torpedo Boat 102 on which Allied Forces commander General Dwight Eisenhower and British Prime Minister Winston Churchill inspected warships before the 1944 D-Day invasion of Nazi-occupied France.

The flotilla passed under 14 bridges and past landmarks including the Houses of Parliament, St Paul's Cathedral, and the Tower of London, after the picturesque Tower Bridge bascules were raised in salute.

Another boat taking part, "Amazon", featured in diamond jubilee celebrations for Queen Victoria, Elizabeth's great-great-grandmother, held in 1897 when Britain's empire spanned much of the globe.

The jubilee pageant appeared on news sites around the world and was among the top trending topics on the Twitter micro blogging site, with messages ranging from congratulatory to comic.

"Booze cruise" wrote @Queen_UK, an irreverent and unofficial spoof twitter handle written from the queen's perspective.

Although the queen is still head of state in 16 countries from Australia and Canada to tiny Tuvalu in the Pacific Ocean and head of the Commonwealth, Britain is a shadow of its former imperial self.

Nevertheless, interest in the pageant and affection for Queen Elizabeth extended to former colonies such as Canada.

"I admire Queen Elizabeth II for her extraordinary grace and diligence," marketing expert Amanda Batchelor told Reuters from her home in Toronto where she was watching on television.

"The fact that she remains relevant to millions of people - in the UK and abroad - over six decades of rapid change is testimony to her longevity. She is a sign of stability and security. She is a kind of living history."

Historians and commentators say the pomp and spectacle of British royal occasions gives the country a sense of national pride at a time when the economy is in recession and people face deep austerity measures.

STREET PARTIES

Across England, Scotland, Wales and Northern Ireland, street parties were being held to mark the occasion. Prince Charles and his wife Camilla dropped into one in central London before the pageant, joining in a rousing rendition of the national anthem.

While the queen and the royal party braved the elements under a golden canopy on a barge in the middle of the Thames, the wet conditions proved too much for Prime Minister David Cameron, who moved his Downing Street party indoors.

That said, the government hoped the festivities would mark the start of a summer of revelry capped off by the Olympic Games in London, raising the public's spirits and their poll ratings.

"What is great is that we have the jubilee and then the Olympics. We should show how great we are in Britain," said Joanne Richmond, 61, from central England, who was in London for the queen's coronation as a two-year-old.

However, economists have warned that the extra public holidays will hit Britain's already ailing economy, potentially prolonging a recession.

The celebrations come as polls show the overwhelming backing for the monarchy, which has overcome a slump in the 1990s following marital infidelities and the death of the hugely popular Princess Diana in a 1997 Paris car crash

However, not everyone in London was cheering as about 100 republicans waving banners demanding "Votes not Boats" and "Make Monarchy History" staged a protest near Tower Bridge.

"Her achievement is just staying alive, doing little and saying less," Graham Smith, head of campaign group Republic, told Reuters.

Even republicans acknowledge there is almost no chance that the queen will be ousted and take solace in indications many Britons are simply indifferent -- 2 million people are leaving the country to take advantage of the extended public holiday.

Celebrations will continue on Monday with a pop concert outside Elizabeth's London residence Buckingham Palace and conclude with a service of thanksgiving at St. Paul's Cathedral on Tuesday followed by a carriage procession.

(Additional reporting by Jeremy Gaunt, Philip Baillie, Peter Griffiths and Ethan Bilby, editing by Paul Casciato)