The Principality of Polotsk, also known as the Kingdom of Polotsk or the Duchy of Polotsk was a medieval principality of the Early East Slavs. It was considered one of the principalities in the Kievan Rus'. It had a wide degree of power to make its own rules. It was started around the ancient town of Polotsk. It is not clear the date it started. Polotsk is mentioned in the mid 9th century as part of Novgorod. In the second half of 10th century Polotsk was ruled by its own dynasty. The first ruler that is mentioned in the history was a semi-legendary Rogvolod (? - 978). Rogvolod is better known as the father of Rogneda. The Principality was in several succession crises of the 11-12th centuries and a war with the Land of Novgorod. By the 13th century it was added into the Grand Duchy of Lithuania. At the time it was largest the principality stretched over large parts of today's northern and central Belarus and a smaller part of today's southeastern Latvia.