The Italo-Turkish War (Turkish: Trablusgarp Savaşı, "Tripolitanian War", Italian: Guerra di Libia, "War of Libya"), also known as the Turco-Italian War, was fought between the Kingdom of Italy and the Ottoman Empire from 29 September 1911 to 18 October 1912. As a result of this conflict, Italy captured coastal areas of the Ottoman Tripolitania Vilayet, of which the main sub-provinces were Fezzan (Turkish: Fizan), Cyrenaica (Turkish: Sirenayka), and Tripoli (Turkish: Trablusgarp) itself. These territories became the colonies of Italian Tripolitania and Cyrenaica, which would later merge into Italian Libya.
During the conflict, Italian forces also occupied the Dodecanese islands in the Aegean Sea. In the 1912 Treaty of Ouchy, which ended the war and gave Italy the possession of Libya, the Italians agreed to return the Dodecanese to the Ottoman Empire. However, the vagueness of the text, combined with subsequent adverse events unfavourable to the Ottoman Empire (the outbreak of the Balkan Wars and World War I), allowed a provisional Italian administration of the islands, and Turkey eventually renounced all claims on these islands in Article 122 of the Treaty of Sèvres (1920), confirmed by Article 15 of the 1923 Treaty of Lausanne.