Royal barge Gloriana to be launched on Thames in London

The boat that will the lead the Thames Diamond Jubilee Pageant is to be launched on the river later.

The 88ft (27m) royal barge Gloriana has been escorted through the streets of London on the back of a truck.

It has been transported from a boatyard to Isleworth, west London, where it will be placed in the water.

A pageant of more than 1,000 boats involving some 20,000 people will sail down the Thames on 3 June to mark the Queen's 60 years on the throne.

The pageant, from Wandsworth to Tower Bridge, will be led by Gloriana, a rowbarge which will be powered by 18 oarsmen.

It will feature a seven-mile long procession of Dunkirk little ships, historic vessels, steam boats and tugs.

The Gloriana will carry royals other than the Queen who have not been named yet, but are likely to be the Prince of Wales and the Duchess of Cornwall, the Duke and Duchess of Cambridge, and Prince Harry.

Music is a key feature of the celebrations, with pieces commissioned for the pageant receiving their premiere on special musical barges.

Carol Ann Duffy, the poet laureate, has written the words for a new song with music by composer Orlando Gough.

Ten film composers, including Downton Abbey composer John Lunn, were commissioned to devise a new movement inspired by the original titles of Handel's Water Music.

The flotilla will feature 20,000 people on the water, travel under 14 bridges and take 90 minutes to pass any given point.