The Treaty of Bucharest was a peace treaty which the German Empire forced Romania to sign on May 7, 1918. Among its terms: * Romania had to return Southern Dobruja and to cede the southern part of Northern Dobruja to Bulgaria, while the rest of the province remained under the joint control of the Central Powers. * Romania had to give Austria-Hungary control of the passes of the Carpathian Mountains. * Romania had to lease its oil wells to Germany for 90 years. * The Central Powers recognized the Union of Bessarabia with Romania.