The Diamond Jubilee Pageant on the Thames promises to be a one of the greatest spectacles the river has ever seen.
The 1,000-boat extravaganza, with the Queen on a throne on the Royal Barge as the centrepiece of the seven-mile-long flotilla, is expected to be watched by millions.
Historian David Starkey, who is curating an exhibition for the Queen's Diamond Jubilee at the National Maritime Museum in Greenwich, looks at how the royals' relationship with the river has changed over time.
"When the Queen makes her procession down the river to celebrate the Jubilee, she will be following in the footsteps of generations of her family," he said.
One of the highlights of Royal River: Power, Pageantry and the Thames is Canaletto's London: The Thames on Lord Mayor's Day, looking towards the City and St Paul's Cathedral, which is on loan for the first time to the UK.
The exhibition runs until September 9.