Which historic event in Russia began on International Women's Day in 1917?

The historic event in Russia that began on International Women’s Day in 1917 was the February Revolution.

On 8 March 1917 in the Gregorian calendar—23 February in Russia’s Julian calendar—women textile workers in Petrograd left their jobs and protested over food shortages, war, and political repression. Their demonstrations helped trigger wider strikes and unrest, turning a women-led protest into a revolution.

The February Revolution forced Tsar Nicholas II to abdicate and ended centuries of Romanov rule. It produced a Provisional Government, but did not end Russia’s involvement in World War I. The later October Revolution, in November 1917 by the Gregorian calendar, brought the Bolsheviks to power. That date difference explains why the February Revolution is sometimes called the March Revolution outside Russia.