Although there were clashes between British and German forces over colonial possessions in Africa, the bulk of British forces outside the Western Front were fighting in the Dardanelles, Mesopotamia, Egypt, Palestine, Salonika and Italy.
At the end of April 1916 a British and colonial force at Kut-al-Amara in Mesopotamia had been forced to surrender. Colonial forces regrouped and reorganised until December. The Turks held the north bank of the Tigris from the region of Sannaiyat to the area of Kut-al-Amara itself, preventing any British move up the Tigris to Baghdad.
During January and February 1917 the Turks were forced out of their positions by British and colonial forces. By 12 March the British had occupied Baghdad; after a month the region around Baghdad had been secured and in September the British moved against Ramadi on the upper Euphrates River. At the beginning of 1918 British forces concentrated efforts on strategic defence and operations to destroy Turkish positions in upper Mesopotamia.
In October 1918 forces advanced up the Tigris and by the end of the month colonial troops had occupied Kirkuk. The main Turkish position north of Sharqat was successfully attacked on 29 and 30 October 1918, bringing about the armistice with Turkey on 31 October.
The British position in Egypt at the end of 1916 was mainly defensive. In July a Turkish attack on Romani had failed. Positions held by British and colonial forces along the Sinai Peninsula were gradually recovering, and much effort was put into improving water supplies by rail and pipeline in preparation for an attack on El Arish. In December 1916 as the colonial Egyptian Expeditionary Force (EEF) were preparing to attack, Turkish forces withdrew.
In January 1917 the EEF moved up to the Palestinian border and prepared to attack the Turks. In March, Gaza was attacked, but the colonial forces forced to retreat. Gaza was now part of a 12-mile long defensive position, and during the second battle in April, the EEF troops were again unable to make gains. Reinforcements and a new commander, Sir Edmund Allenby, arrived in June 1917.
In October 1917 Allenby was ready to renew the EEF offensive towards Jerusalem. The Third Battle of Gaza finally unhinged the Turkish defensive positions between Gaza and Beersheba, and on 9 December 1917 Turkish forces in Jerusalem surrendered to the EEF. The German Spring offensives of 1918 on the Western Front prevented any further meaningful offensive by the EEF until September. The Battle of Megiddo in September 1918 broke through Turkish defences and opened the way to Damascus, which was captured by British and colonial forces on 1 October 1918.