The history of Moldova can be traced to the 1350s, when the Principality of Moldavia, the medieval precursor of modern Moldova and Romania, was founded. The principality was a vassal of the Ottoman Empire from 1538 until the 19th century. In 1812, following one of several Russian-Turkish wars, the eastern half of the principality, Bessarabia (where most of today's Moldova is located), was annexed by the Russian Empire.