Principality of Polotsk
History of Belarusian states can be traced far to Principality of Polotsk. From 13th century lands of modern Belarus were a major part of the Grand Duchy of Lithuania which later became part of the Polish–Lithuanian Commonwealth. In 19th century Belarus together with Lithuania formed the Northwestern Krai of Russian Empire. At the beginning of the 20th century there was the short-lived Belarusian People's Republic, and in 1922 Belarus became part of the USSR as Belarusian SSR except West Belarus, which was under Polish rule, which was briefly interrupted due to Soviet occupation during the Polish-Soviet War. In 1991, Belarus regained its independence.