Following Turkish and Russian wars, much of Moldova was transferred to Russian control and called Bessarabia in 1812. In 1917, Bessarabia proclaimed the independent Democratic Republic of Moldova and united with Romania in 1918. In 1924, the USSR established the Moldovan Autonomous Oblast on the east of the Dniester River in the Ukrainian Soviet Socialist Republic. Shortly afterwards, the oblast’s status was altered into the Moldovan Autonomous Soviet Socialist Republic (MASSR). At the beginning of World War II, the Soviet forces occupied Bessarabia and rejoined it to the MASSR, thereby forming the Moldovan Soviet Socialist Republic. During World War II Moldova returned to Romania, but was handed over to the USSR in 1947. Following the collapse of the Soviet Union, Moldova finally became independent on 27 August 1991.
Constitutional history of Moldova