The acronym ANZAC refers to the Australian and New Zealand Army Corps. This term also refers to the soldiers in this army, who were called Anzacs.
ANZAC Day, which is on April 25 of each year, commemorates the first military engagement of the ANZAC forces that occurred during World War 1. ANZAC forces landed on Gallipoli on April 25, 1915, to fight against the Ottoman Turks who were allies with Germany. The main objective of the allied forces was to capture Constantinople. The Gallipoli Campaign lasted eight months. It was a disastrous campaign in which more than 8000 ANZAC soldiers lost their lives.
In 1916, April 25 became ANZAC Day, a national day that recognized and remembered the soldiers who had died.