Treaty of Mondros was signed between Ottoman Empire and the Entente Powers on October 30th 1918 after the Ist World War conducted from 1914 to 1918. It was decided to meet in Lausanne, Switzerland to make an indelible peace in conseguence of Treaty of Mudanya which was signed on October 11th 1922. The matter of Mosul was a problem between Turkey and Britain during the meeting of peace in Lousanne. Turkey tired to prove that Mosul belonged to her whith its historical period. The matter of Mosul couldn’t be solved in Treaty of Lausanne. The league of nations postponed the matter of Mosul for 9 months between Turkey and Britain because they didn’t want to interfere to the peace treaty Turkey and Britain orgaized Treaty of Halic in 1924. It was drawn a temporary borderline called the Line of Brussel between Britain and Turkey to prevent body events. Britain encouraged the Nasturi and Sheikh Said riots not to give Mosul to Turkey. Mosul was given to Iraq as British mandate in Exchange for 500. 000 British pound with the Treaty of Ankara signed in 1926.