Bessarabia is a historical region in Eastern Europe bounded by the Dniester River on the north and east and the Prut River on the west and the Black Sea on the south. It is currently split between Ukraine and Moldova.
This was the name by which Imperial Russia designated the eastern part of the Principality of Moldavia, ceded by the Ottoman Empire to Russia at the Peace of Bucharest in 1812. While this eastern part became the Governorate of Bessarabia, the western part of Moldavia united with Wallachia in 1859 in what would become the Kingdom of Romania. For a short period between 1856 and 1878, two of the nine traditional counties of Bessarabia were also part of Moldavia and then Romania.
In 1918, shortly before the end of World War I, Bessarabia declared its independence from Russia as the Moldavian Democratic Republic, and after three months united with the Kingdom of Romania. In 1940, Bessarabia was occupied by the USSR. Romania recaptured it in 1941 and lost again in 1944. In 1947, the Soviet-Romanian border set along the Prut River was internationally recognised by the Paris Treaty that ended World War II. The core part of Bessarabia was joined with parts of the Moldavian ASSR (Transnistria) to form the Moldavian SSR. At the same time, smaller parts of Bessarabia, in the south (two traditional counties; Budjak) and north (half of one county), were transferred to the Ukrainian SSR.
During the process of dissolution of the Soviet Union, the Moldavian SSR declared itself sovereign (23 June 1990) and declared independence from the USSR on 27 August 1991, becoming the Republic of Moldova. The areas allotted to the Ukrainian SSR in 1940 became part of the new independent Ukraine since 1991, while the area roughly corresponding to Transnistria became the self-proclaimed Pridnestrovian Moldavian Republic and is not controlled by the government of the Republic of Moldova.