Empire took advantage of the European powers' preoccupation with the war and conducted large-scale ethnic cleansing of the indigenous Armenian, Greek, and Assyrian Christian populations, known as the Armenian genocide, Greek genocide, and Assyrian genocide. The British and French opened overseas fronts with the Gallipoli (1915) and Mesopotamian campaigns (1914). In Gallipoli, the Ottoman Empire successfully repelled the British, French, and Australian and New Zealand Army Corps (ANZACs). In Mesopotamia, by contrast, after the defeat of the British defenders in the siege of Kut by the Ottomans (1915–16), British Imperial forces reorganised and captured Baghdad in March 1917. The British were aided in Mesopotamia by local Arab and Assyrian fighters, while the Ottomans employed local Kurdish and Turcoman tribes. Further to the west, the Suez Canal was defended from Ottoman attacks in 1915 and 1916; in August, a German and Ottoman force was defeated at the Battle of Romani by the ANZAC Mounted Division and the 52nd (Lowland) Infantry Division. Following this victory, an Egyptian Expeditionary Force advanced across the Sinai Peninsula, pushing Ottoman forces back in the Battle of Magdhaba in December and the Battle of Rafa on the border between the Egyptian Sinai and Ottoman Palestine in January 1917. Russian armies generally had success in the Caucasus campaign. Enver Pasha, supreme commander of the Ottoman armed forces, was ambitious and dreamed of re-conquering central Asia and areas that had been lost to Russia previously. He was, however, a poor commander. He launched an offensive against the Russians in the Caucasus in December 1914 with 100,000 troops, insisting on a frontal attack against mountainous Russian positions in winter. He lost 86% of his force at the Battle of Sarikamish. The Ottoman Empire, with German support, invaded Persia (modern Iran) in December 1914 in an effort to cut off British and Russian access to petroleum reservoirs around Baku near the Caspian Sea. Persia, ostensibly neutral, had long been under the spheres of British and Russian influence. The Ottomans and Germans were aided by Kurdish and Azeri forces, together with a large number of major Iranian tribes, such as the Qashqai, Tangistanis, Lurs, and Khamseh, while the Russians and British had the support of Armenian and Assyrian forces. The Persian campaign was to last until 1918 and end in failure for the Ottomans and their allies. However, the Russian withdrawal from the war in 1917 led to Armenian and Assyrian forces,