The Duke of Cambridge and The Princess Royal are set to mark Anzac Day on Sunday, remembering all Australians and New Zealanders killed in war and honouring returned servicemen and women.
The commemorative occasion on 25 April is the anniversary of the first major military action fought by the two Commonwealth countries in the First World War.
ANZAC stands for Australia and New Zealand Army Corps and was formed in 1915.
Princess Anne, accompanied by her husband, Vice Admiral Sir Tim Laurence, will attend two commemorative services in London on behalf of the Royal Family.
In the early hours of 25 April, the Princess and Vice Admiral will attend the Anzac Day Dawn Service at Wellington Arch.
At the service, Her Royal Highness will lay a wreath at both the Australian and New Zealand War Memorials and sign a Book of Remembrance.
Anne and the Vice Admiral will then attend the Anzac Day Service of Commemoration and Thanksgiving at Westminster Abbey.
Ahead of the commemorations, the Duke of Cambridge sent a message to mark Anzac Day to the New Zealand and Australian High Commissions in London.
"This Anzac Day, Catherine and I join Australians and New Zealanders across the world to remember and honour the servicemen and women of the Australian and New Zealand Army Corps," Prince William said.
"Today we stand together to reflect not only on their sacrifices, but also their courage, sense of duty, and their famously indomitable spirit.
"Though many will still be unable to come together in person this year, we are heartened in the knowledge that Australians and New Zealanders will continue to commemorate those who have given so much for our freedoms.
"The ANZAC qualities of endurance, courage, ingenuity, good humour and mateship are admired as fiercely as ever before.
"Lest we forget."
ANZAC forces landed on Gallipoli on 25 April 1915, meeting tough resistance from the Ottoman Turkish defenders.
The Australian and New Zealand Army Corps' success effectively put an end to the Germans' 1918 spring offensive.
Each year, dawn services are held in Australia, New Zealand, France, the UK and Turkey to remember those who died during the landing at Gallipoli peninsula in Turkey 106 years ago.
Cover image: Prince William on Anzac Day 2019 (Picture: Kensington Palace).