The Principality of Polotsk (obsolete spelling: Polock; Belarusian: По́лацкае кня́ства, romanized: Polackaje kniastva; Latin: Polocensis Ducatus), also known as the Duchy of Polotsk or Polotskian Rus', was a medieval principality. The origin and date of the establishment of the state are uncertain. Chronicles of Kievan Rus' mention Polotsk being conquered by Vladimir the Great, and thereafter it became associated with Kievan Rus' and its ruling Rurikids.
The principality was supposedly established around the town of Polotsk (now in Belarus) by the tribal union of Krivichs. In the second half of the 10th century, Polotsk was governed by its own dynasty; its first ruler mentioned in the chronicles was the semi-legendary Rogvolod (?–978), better known as the father of Rogneda. The principality was heavily involved in several succession crises of the 11th–12th centuries and a war with the Novgorod Land. By the 13th century, it was integrated into the Grand Duchy of Lithuania.