 On 19 May 1915 , the Turkish launched an assault against the Anzac perimeter . Forewarned by naval reconnaissance aircraft , the troops were on alert and the position was reinforced by the return of the 2nd and New Zealand Infantry Brigades from Cape Helles and the arrival of the 1st Light Horse Brigade and New Zealand Mounted Rifles Brigade from Egypt . Along most of the line , the attack met with immediate disaster , with the Turkish attackers swept away by the rifle and machine gun fire of the Anzac defenders . At Courtney 's Post , one of the most exposed parts of the perimeter , the Turks managed to enter the trenches but there they encountered Lance Corporal Albert Jacka and others , who drove them out again . For his action , Jacka became the first Australian to win the Victoria Cross in the war . 
