As the Russian Empire noticed the weakening of the Ottoman Empire, it occupied the eastern half of the autonomous Principality of Moldavia, between the Prut and Dniester rivers. This was followed by six years of warfare, which were concluded by the Treaty of Bucharest (1812), by which the Ottoman Empire acknowledged the Russian annexation of the province.^[73]

In 1814, the first German settlers arrived and mainly settled in the southern parts, and Bessarabian Bulgarians began settling in the region too, founding towns such as Bolhrad. Between 1812 and 1846, the Bulgarian and Gagauz population migrated to the Russian Empire via the River Danube, after living many years under oppressive Ottoman rule, and settled in southern Bessarabia. Turkic-speaking tribes of the Nogai horde also inhabited the Budjak Region (in Turkish Bucak) of southern Bessarabia from the 16th to 18th centuries but were totally driven out prior to 1812. Administratively, Bessarabia became an oblast of the Russian Empire in 1818, and a guberniya in 1873.