New Zealand Prime Minister John Key (L) and Australian Prime Minister Tony Abbott stand for a moment of silence after laying wreaths during the Commonwealth and Irish Memorial Service at Cape Helles on April 24, 2015 in Seddulbahir, Turkey. Turkish and Allied powers representatives, as well as family members of those who served, are commemorating the 100th anniversary of the Gallipoli campaign with ceremonies at memorials across the Gallipoli Peninsula. The Gallipoli land campaign, in which a combined Allied force of British, French, Australian, New Zealand and Indian troops sought to occupy the Gallipoli Peninsula and the strategic Dardanelles Strait during World War I, began on April 25, 1915 against Turkish forces of the Ottoman Empire. The Allies, unable to advance more than a few kilometers, withdrew after eight months. The campaign cost the Allies approximately 50,000 killed and up to 200,000 wounded, the Ottomans approximately 85,000 killed and 160,000 wounded.