Answer :

The Bolshevik Revolution occurred in 1917. This revolution took place in Russia and led to the overthrow of the Provisional Government and the establishment of the Soviet Union. Here's a breakdown of the events surrounding the Bolshevik Revolution:

1. Background: The Bolshevik Revolution was part of the larger Russian Revolution of 1917. It was characterized by widespread discontent among the Russian population due to factors like food shortages, World War I casualties, and political instability.

2. October Revolution: The Bolsheviks, led by Vladimir Lenin, seized power in Petrograd (now St. Petersburg) on October 25, 1917, according to the Julian calendar then in use in Russia (which corresponds to November 7 in the Gregorian calendar).

3. Establishment of Soviet Rule: Following the October Revolution, the Bolsheviks established Soviet rule, marking the beginning of the Communist era in Russia. Lenin became the leader of the new government.

4. Civil War: The Bolsheviks faced opposition from anti-communist forces known as the Whites in a civil war that lasted until 1922. The Bolsheviks, who later became the Communist Party, emerged victorious, consolidating their power.

Therefore, the correct answer to the question is 1917.