Which major event did Lenin lead that significantly changed Russian governance?

The event that Lenin led, which significantly changed Russian governance, is the October Revolution. This revolution occurred in 1917 and was a pivotal moment in Russian history. It was part of a broader series of events that followed the February Revolution earlier that year, which had led to the abdication of Tsar Nicholas II and the establishment of a provisional government.

Lenin and the Bolshevik Party sought to implement a more radical socialist agenda than the provisional government was willing to pursue. The October Revolution involved a well-planned coup where the Bolsheviks seized power in Petrograd (now St. Petersburg) on October 25, 1917 (Julian calendar) by taking control of key locations such as government offices, communication centers, and eventually the Winter Palace.

This revolution brought about the establishment of one of the world's first communist states and set the stage for significant changes in governance, culminating in the eventual creation of the Soviet Union. Lenin's leadership during the October Revolution was crucial, as it aligned the working class and soldiers behind the Bolshevik vision of a radical restructuring of society based on Marxist principles.

The other events mentioned, such as the Great War, indirectly contributed to the conditions leading to the revolution but were not led