The landing at Anzac Cove on Sunday , 25 April 1915 , also known as the landing Self_motion at Gaba Tepe , and to the Turks as the Arıburnu Battle Hostile_encounter , was part of the amphibious invasion Hostile_encounter of the Gallipoli Peninsula by the forces of the British Empire , which began Process_start the land phase of the Gallipoli Campaign of the First World War Hostile_encounter .