Who had a successful revolution in the early 19th century

The soviet union had a revolution immediatily after the war that replaced Czars rule with a more dictatorial form of governance under the communist party led by Stalin and Lenin. The revolution was horrendous as it led to the masaccre of Czar Nicholus family in cold blood. The society did not emerge from the revolution stronger and it was only until Gorbachef time that real changes were felt.