The significant political change that occurred in Russia in 1917 was the Bolshevik Revolution, which led to the overthrow of the Provisional Government and the establishment of a communist regime. The revolution occurred in two key phases: the February Revolution, which ended the Tsarist autocracy, and the October Revolution, led by Vladimir Lenin and the Bolsheviks. This change marked the beginning of a new political order in Russia, resulting in the creation of the Soviet Union. It fundamentally altered the political landscape of the country, leading to years of civil war, the redistribution of land, and the nationalization of industries.