ANZAC stands for Australian and New Zealand Army Corps. The soldiers in those forces became known as ANZACs. Anzac Day is a commemoration of the anniversary of the landing of Australian and New Zealand troops at Gallipoli, Turkey on 25 April in 1915. When Great Britain declared war against Germany for its invasion of Belgium in 1914, Australia and New Zealand, as Dominions within the British Empire, regarded themselves automatically also at war.