British Queen Elizabeth II on Sunday took part in the largest event held to celebrate her 60 years as queen by leading a flotilla of boats in a pageant down the River Thames through central London.

Britain's Queen Elizabeth (C) arrives at Chelsea Pier on the River Thames, in London June 3, 2012. Britain's Queen Elizabeth joined an armada of 1,000 boats in a gilded royal barge, in a pageant down the River Thames on Sunday in a spectacular highlight of four days of nationwide celebrations to mark her Diamond Jubilee. [Photo/Agencies]

The Queen sailed on the barge the Spirit of Chartwell accompanied by her husband Prince Philip, and members of her immediate family including heir to the throne Prince Charles, and his sons Prince William and Prince Harry, and William's wife Katherine, Duchess of Cambridge.

The Queen, aged 86, led a thousand boats in one of the largest flotilla of boats seen on the Thames since the reign of Charles II in 1662.

The pageant began at 2 p.m., on the Thames in the west London district of Battersea, and travelled 11 km eastwards down the river towards the sea through central London to the Tower of London.

The Spirit of Chartwell, about 25 meters long and four meters wide, was decorated with flowers and gilded carvings and flew the royal flag at its prow.

Also at the front of the pageant was a barge containing a peal of eight church bells, some weighing several tonnes and each named after a member of the royal family. Bellringers performed the highly unusual task of ringing peals on the bells as the boat processed down the Thames.

Among the thousands of crewmen on the thousand boats was Sir Steve Redgrave, the five-times gold medal-winning rowing champion, who led a handpicked team of rowers on the specially-commissioned royal row-barge Gloriana.

The weather was overcast all day in London, with rain at times. Across the country street parties were held in celebration, despite overcast weather and rain at times.

A special street party was scheduled for the prime minister's residence in Downing Street hosted by David Cameron, but at the last minute the party was moved indoors because of rain.

Ahead of the pageant, several dozen anti-monarchist supporters gathered on the Thames embankment opposite the Tower of London carrying placards saying "democracy not monarchy" and "power to the people."

Graham Smith, director of anti-monarchist group Republic which organized the protest, told Xinhua, "We have been gearing up for the Diamond Jubilee for the past few years and we've gained quite a bit of support off the back of it."

Smith added, "The outcome for the republican movement is that we will be bigger and stronger than before. The high level of coverage in the media only provokes people to think about it and to come and find us."

The Queen came to the throne on Feb. 6, 1952 and her coronation took place on June 2 1953.

She celebrated her Silver Jubilee, marking 25 years as queen in 1977, and her Golden Jubilee, marking 50 years, in 2002.

The only other British monarch to celebrate a Diamond Jubilee was Queen Victoria in 1897.