The Mesopotamian campaign was a campaign in the Middle Eastern theatre of World War I fought between the Allies represented by the British Empire, mostly forces from India, and the Central Powers, mostly of the Ottoman Empire. The first British offensive began on 6 November 1914 and the fighting lasted until the capitulation of the Ottoman Empire in October 1918. The 1st Australian Wireless Signal Squadron as well as the Mesopotamian Half-Flight (Australian Flying Corps) were Australian units that served during the campaign.