Britain's royal family will again pay tribute to Australian and New Zealand servicemen and women at a special Anzac Day service at Westminster Abbey.
The Duchess of Cambridge will attend a commemoration and thanksgiving service at the London church at noon on Thursday, continuing a 103-year tradition started by King George V and Queen Mary.
The Duke of Gloucester, the Queen's first cousin and colonel-in-chief of the Royal Australian Army Education Corps and the Royal New Zealand Army Medical Corps, will also attend.
Anzac Day will begin in the UK with a Dawn Service at 5am local time (1400 AEST) at the New Zealand War Memorial on Hyde Park Corner.
At 11am, a requiem will be read at the Whitehall Cenotaph followed by a wreath-laying ceremony attended by Australian High Commissioner George Brandis, his New Zealand counterpart Sir Jerry Mateparae and British government representatives.
The Westminster Abbey service will follow at noon.
Commemorations will also occur in Bath, Cambridge, Hull, Norwich, Peterborough, Staffordshire, Manchester, Edinburgh and the Channel Island of Jersey to mark the anniversary of Britain's disastrous Gallipoli Campaign, where 60,000 Australian and 16,000 NZ troops first saw major action in the First World War.
At Gallipoli in Turkey, where 11,430 Anzacs were killed and 24,193 injured between 1915-1916, crowds of up to 1500 people are expected to attend a Dawn Service.
Later, there will be an Australian commemoration at the Lone Pine Memorial and a NZ commemoration at Chunuk Bair Memorial.
However, all Turkish nationals except dignitaries have reportedly been banned from this year's services as a security precaution amid fears of terror attacks.
The Australian reports visitor numbers were actually set to be higher before Turkish President Recep Tayyip Erdogan's threats to visitors during an election campaign speech following the Christchurch terror attack.
"Your grandfathers came and saw that we're here. Then some of them walked back, while others left in coffins," Erdogan, referring to the Anzacs, told Andolu Agency.
"If you come with the same intention, we'll be waiting for you."
The comments sparked diplomatic rows with Australia and New Zealand, where the comments caused great offence, but relations have since improved.
In France, there will be a Dawn Service at the Australian War Memorial at Villers-Bretonneux, where Australian troops helped recapture the French village from the Germans on April 25, 1918.
In Belgium, there will be another Dawn Service at Polygon Wood followed by a wreath-laying ceremony at nearby Tyne Cot Cemetery, the largest Commonwealth war cemetery in the world.
An Anzac Service and Last Post ceremony will be held at the Menin Gate at Ypres at 11.10am (1910 AEST) before another wreath-laying ceremony at the Belgium War Memorial in the same town.
At 3.15pm there will be a final commemoration service at the Toronto Avenue Cemetery near Ypres.
Other Anzac Day services are also set for Copenhagen in Denmark, Oslo in Norway and Dublin in Ireland.
Australian Associated Press