Adakale Island in River Danube was forgotten during the peace talks at the Congress of Berlin in 1878, which allowed it to remain a de jure Turkish territory and the Ottoman Sultan Abdülhamid II's private possession until the Treaty of Lausanne in 1923 (de facto until Romania unilaterally declared its sovereignty on the island in 1919 and further strengthened this claim with the Treaty of Trianon in 1920.)[1] The island was submerged during the construction of the Iron Gates hydroelectric plant in 1970, which also removed the possibility of a potential legal claim by the descendants of Abdul Hamid II.