Final answer:
The capital of tsarist Russia before the Communist Revolution in 1917 was St. Petersburg, which was later renamed to Petrograd and then Leningrad.
Step-by-step explanation:
Before the Communist Revolution in 1917, the capital of tsarist Russia was St. Petersburg. This city was established as the forward capital by Czar Peter the Great in the 18th century. However, after the Bolshevik Revolution, led by Vladimir Lenin, the capital was moved from St. Petersburg, which had been renamed to Petrograd (and later Leningrad), back to Moscow. The Bolsheviks, promising peace, land, and bread, overthrew the provisional government and established a Marxist totalitarian state, which became the Union of Soviet Socialist Republics (USSR).