Polotsk (pôˈlətsk) [key], city (1989 pop. 76,837), W Belarus, on the Western Dvina River at its confluence with the Polota. It is a large rail junction and agricultural trade center. Manufactures include building materials, farm implements, processed foods, metal goods, and glass filaments. One of Russia's oldest cities, Polotsk was the capital of a principality of the same name from the 10th to 13th cent., when it passed to Lithuania. Polotsk became self-governing in 1498. A flourishing center for trade, first with Scandinavia, Novgorod, and Pskov and then (13th-16th cent.) with Riga, Polotsk was transferred to Russia in 1772. The city retains the Cathedral of Sofia (1044–66) and the Cathedral of the Spaso-Evfrosina monastery (12th cent.).