Prince Harry has laid a wreath during a dawn service at Wellington Arch to mark the start of Anzac Day commemorations in the UK.
Thousands of people waited in the dark before the start of proceedings, which marked 100 years since the day was first marked in London.
Anzac Day has been commemorated in the capital since the first anniversary of the Anzac landings at Gallipoli in 1916, when King George V attended a service at Westminster Abbey.
Since then, the services have become an important moment for thousands of expatriate and visiting New Zealanders and Australians, who honour the sacrifices of their countrymen and women in all wars.
Harry laid a wreath at the memorial at Hyde Park Corner, followed by the New Zealand and Australian high commissioners and other dignitaries.
Addressing the gathered crowds, Alexander Downer, Australian high commissioner to the UK, said: "When we reflect on Anzac Day we imagine the Gallipoli landings, what it must have been like, at dawn on the water, in sight of that rugged shoreline – and a collectively held breath, a leaden silence about to be broken.
"We consider the enthusiasm, the courage, and the heroism of the Anzac troops – ordinary men fighting for God, King and empire, for their mates, for adventure, for a world without war."
He added that the full meaning of Anzac Day was best encapsulated in an open letter from Australian poet Banjo Patterson to the Anzac troops in the Dardenelles in 1915.
It starts: "Australia takes her pen in hand
"To write a line to you,
"To let you fellows understand
"How proud we are of you..."
Harry will later attend a parade at the Cenotaph, where he will lay a wreath on behalf of the Queen, and a service of commemoration and thanksgiving at Westminster Abbey.
Later in the morning, at the wreath laying and parade service at the Cenotaph on Whitehall, Harry will lay a wreath on behalf of the Queen.