The event that initiated the Russian Revolution of 1917 was the February Revolution, which began in late February (Julian calendar) or early March (Gregorian calendar) due to widespread discontent with Tsar Nicholas II's rule, exacerbated by World War I's hardships. Strikes, food shortages, and military failures led to mass protests and the eventual abdication of the Tsar on March 2, 1917. This uprising marked the end of centuries of Romanov rule and led to the establishment of a provisional government. The subsequent October Revolution later that year would further reshape Russian politics and society, leading to the rise of the Bolsheviks.