The Byelorussian Soviet Socialist Republic (BSSR, or Byelorussian SSR; Belarusian: Беларуская Савецкая Сацыялістычная Рэспубліка, romanized: Bielaruskaja Savieckaja Sacyjalistyčnaja Respublika; Russian: Белорусская Советская Социалистическая Республика, romanized: Byelorusskaya Sovyetskaya Sotsialisticheskaya Respublika or Russian: Белорусская ССР, romanized: Belorusskaya SSR), also commonly referred to in English as Byelorussia, was a republic of the Soviet Union (USSR). It existed between 1920 and 1922, and from 1922 to 1991 as one of fifteen constituent republics of the USSR, with its own legislation from 1990 to 1991. The republic was ruled by the Communist Party of Byelorussia and was also referred to as Soviet Byelorussia or Soviet Belarus by a number of historians. Other names for B