 While the northeastern part of Moldavia, called Bukovina, was similarly annexed by the Austrian Empire, the western part of Moldavia remained an autonomous principality, and in 1859, united with Wallachia to form the Kingdom of Romania.In 1856, the Treaty of Paris returned the south of Bessarabia to Moldavia, but in 1878, the Kingdom of Romania returned them to the Russian Empire as a result of the Treaty of Berlin.At the time of annexation, Moldavian population predominated in Bessarabia.