Anzac Day (; or ) is a national day of remembrance in Australia and New Zealand that broadly commemorates all Australians and New Zealanders "who served and died in all wars, conflicts, and peacekeeping operations" and "the contribution and suffering of all those who have served". Observed on 25 April each year, Anzac Day was originally devised to honour the members of the Australian and New Zealand Army Corps (ANZAC) who served in the Gallipoli Campaign, their first engagement in the First World War (1914–1918). History Anzac Day marks the anniversary of the first campaign that led to major casualties for Australian and New Zealand forces during the First World War. The acronym ANZAC stands for Australian and New Zealand Army Corps, whose soldiers were known as Anzacs. Anzac Day remains one of the most important national occasions of both Australia and New Zealand; however, the ceremonies and their meanings have changed significantly since 1915. According to Dr Martin Crotty, a historian at the University of Queensland, Anzac commemorations have "suited political purposes right from 1916 when the first Anzac Day march was held in London and Australia, which were very much around trying to get more people to sign up to the war in 1916–1918." Gallipoli campaign, 1915 In 1915, Australian and New Zealand soldiers formed part of an Allied expedition that set out to capture the Gallipoli Peninsula to open the way to the Black Sea for the Allied navies. The objective was to capture Constantinople, the capital of the Ottoman Empire, which was an ally of Germany during the war. The ANZAC force landed at Gallipoli on 25 April, meeting fierce resistance from the Ottoman Army commanded by Mustafa Kemal (later known as Atatürk). What had been planned as a bold strike to knock the Ottomans out of the war quickly became a stalemate, and the campaign dragged on for eight months. At the end of 1915, the Allied forces were evacuated after both sides had suffered heavy casualties and endured great hardships. The Allied deaths totalled over 56,000, including 8,709 from Australia and 2,721 from New Zealand. News of the landing at Gallipoli made a profound impact on Australians and New Zealanders at home and 25 April quickly became the day on which they remembered the sacrifice of those who had died in the war. Though the Gallipoli campaign failed to achieve its military objectives of