Royals Prince William and Princess Anne to Honor Retired Servicemen and Women After Prince Philip's Death Anzac Day is an annual remembrance day honoring Australians and New Zealanders killed in war By Ally Mauch Published on April 24, 2021 04:00 PM Share Tweet Pin Email Photo: Ian Vogler/AP/Shutterstock; Mark Cuthbert/UK Press via Getty Images Princess Anne will attend two services in London on Sunday in honor of Anzac Day, an annual holiday honoring all Australians and New Zealanders killed in war, as well as retired servicemen and women. Accompanied by Vice Admiral Sir Tim Laurence, the only daughter of Queen Elizabeth and the late Prince Philip, 70, will begin the day at the Anzac Day Dawn Service at Wellington Arch. There, she will lay a wreath at the Australian and New Zealand War Memorials, and sign a Book of Remembrance. Later in the day, Anne will attend the Anzac Day Service of Commemoration and Thanksgiving at Westminster Abbey. Ahead of Sunday's events, Prince William sent a message 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 service men and women of the Australian and New Zealand Army Corps," the Duke of Cambridge said in his statement. Jonathan Brady - Pool/Getty Images Kate Middleton and Prince William Make Surprise Outing with Special Tie to Prince Philip "Today we stand together to reflect not only on their sacrifices, but also their courage, sense of duty, and their famously indomitable spirit," his message continued. "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." William, 38, concluded, "The ANZAC qualities of endurance, courage, ingenuity, good humour and mateship are admired as fiercely as ever before." Anne and William were last together at the funeral of the late Duke of Edinburgh last Saturday. Jonathan Brady - Pool/Getty Images Can't get enough of PEOPLE's Royals coverage? Sign up for our free Royals newsletter to get the latest updates on Kate Middleton, Meghan Markle and more! Jonathan Brady - Pool/Getty Images The day of remembrance commemorates the first major battle involving Australian and New Zealand forces during World War I. It has been honored in London since the first anniversary of the Anzac landings at Gallipoli in 1916, when King George V attended a service at Westminster Abbey. (Anzac is an acronym, standing for the Australian and New Zealand Army Corps). Though the usual commemorative events did not take place last year due to the COVID-19 pandemic, Kate Middleton previously attended the Anzac Day Service of Commemoration and Thanksgiving at Westminster Abbey in 2019 alongside brother-in-law Prince Harry.