1. Also called (reckoned by the Julian calendar): February Revolution
the uprising in Russia in March 1917, during which the tsar abdicated and a provisional government was set up
2. Also called (reckoned by the Julian calendar): October Revolution
the seizure of power by the Bolsheviks under Lenin in November 1917, transforming the uprising into a socialist revolution. This was followed by a period of civil war against counter-revolutionary armies (1918–22), which ended in eventual victory for the Bolsheviks