The Bolshevik Revolution, also known as the October Revolution, was a massive turning point in Russian history. Basically, radical Jews overthrew the Romanov monarchy—who had ruled since the 1600s—and established a repressive communist regime that ended very badly for everyone.

Summary
The Bolsheviks were a faction of the Russian Social Democratic Labour Party, which later became the Communist Party of the Soviet Union. While not all Bolsheviks were Jews, a large number of the Bolshevik leaders and revolutionaries were Jews.
Vladimir Lenon and his revolutionaries overthrew the Romanov monarchy, which had ruled Russia since 1613. The new communist regime very quickly negatively transformed Russian society through forced collectivisation, suppression of religion and state control over all aspects of life.