In 1915 Britain gained the support of Arabs in World War I after promising independence for Arab states. While the Ottoman Empire entered the war on Germany's side, the Arabs (led by Sherif Hussein of Mecca, (also known as Sharif Husayn ibn ‘Ali) agree to side with the Allies (Britain, France, and Russia.) They did so because of an agreement known as the Hussein-McMahon Correspondence in which Britain promises independence to what is now Syria, Palestine (Israel), Jordan, Iraq, and the Arabian Peninsula should the Allies win the war.