What was the primary cause of the Bolshevik Revolution in 1917?

The primary cause of the Bolshevik Revolution in 1917 was the continuous military defeats and political failures experienced by Russia during World War I. The Russian military suffered significant losses, which demoralized the populace and created widespread dissatisfaction with the government. These defeats not only showcased the inadequacies of the Tsarist regime but also highlighted the severe economic strains placed on the country, leading to food shortages and heightened discontent among workers and peasants.

Additionally, the political failures of the provisional government that took over after the abdication of Tsar Nicholas II in early 1917 further fueled revolutionary sentiment. The provisional government struggled to address critical issues such as land reform, withdrawal from the war, and social inequality, which undermined its authority and led to a loss of popular support. This context of military and political crisis created an environment ripe for the Bolsheviks, who promised peace, land, and bread, to seize power in October 1917.