Fighting in the Middle East was made up of several campaigns. The most significant were Egypt, Palestine, Mesopotamia and Arabia.
Much of the Middle East was controlled by the Ottoman Empire, of which Turkey was the centre. When the Ottoman Empire joined the war, Britain wanted to put an end to this influence and had some important reasons for wanting control of certain places in particular. In Egypt Britain needed to protect the Suez Canal, an important waterway for shipping, and in Mesopotamia she had to secure oil supplies to fuel her vast navy.
Fighting in the Middle East lasted until October 1918 when the Ottoman Empire signed an armistice. Although several of the key objectives had been secured by the end of 1917.
In the Middle East the Allies fought against the armies of the Ottoman Empire. Germany sent military advisors to help the Turks. German officers were frequently in command of Turkish forces. The Alliedforces came from all over the British Empire. ANZAC forces (Australia and New Zealand) played an important role in the Middle East campaigns, as did soldiers from India.
In 1920 the Treaty of Sevres divided up the Ottoman Empire between the Allied Powers. Palestine and Mesopotamia became British mandates, which meant Britain would help run the countries until they could govern themselves. Included in the terms for Palestine was the Balfour Declaration, which created a Jewish National Home in Palestine. This is one of the root causes of the conflict between Israel and Palestine today. Syria became a French mandate even though the Arab people had hoped it would become independent.