The only words we can say to veterans are “thank you”, Theresa May has told a ceremony to mark the 75th anniversary of the Normandy invasion.
Her words were echoed by French President Emmanuel Macron, who told D-Day veterans gathered in northern France that we owe them “our freedom”.
The day of commemorative events began with a lone piper marking the moment the first UK soldiers went ashore.
Donald Trump later told US veterans they were “the pride of the nation”.
The US president was at a service at the US war cemetery at Omaha Beach.
Hundreds of veterans are gathered in Normandy for the anniversary of the largest combined land, air and naval operation in history.
The day’s commemorations mark key events in the operation, which was aimed at bringing an end to World War Two.
By night-time on 6 June 1944, about 156,000 Allied troops had landed on Normandy’s beaches, despite challenging weather and fierce German defences. Some had drowned when they were accidentally dropped off too soon in deep waters.
By the end of D-Day, the Allies had established a foothold in France and within 11 months Nazi Germany was defeated and the war was over.
At 06:26 BST – the exact minute the first British troops landed on the beaches in 1944 – a lone piper played on a section of the Mulberry Harbour in the town of Arromanches.
Mr Macron and Mrs May – in one of her final engagements as Conservative leader – were in Ver-sur-Mer to see the first stone laid for a memorial to commemorate the 22,442 British troops who died there in the summer of 1944.
The memorial, which overlooks Gold Beach, depicts three soldiers advancing across the beach