Leon Trotsky was a key figure in the Russian Revolution and the early Soviet Union, known for his role as a Marxist revolutionary and theorist. Born in 1879 in what is now Ukraine, Trotsky was an early supporter of the Bolshevik movement alongside Vladimir Lenin. He played a crucial role in the October Revolution of 1917 and later became the leader of the Red Army, contributing significantly to the Bolshevik victory in the civil war. As a theorist, Trotsky developed the concept of "permanent revolution," arguing that socialist revolutions could not be confined to one country alone but should be a global movement. His ideas were often at odds with those of Joseph Stalin, leading to intense political conflict. Trotsky eventually fell out of favor within the Communist Party and was exiled in 1929. Despite his exile, Trotsky continued to advocate for his revolutionary ideas and critique Stalin's policies, which he viewed as bureaucratic and oppressive. His writings from this period remain influential in various leftist movements. Trotsky was assassinated in Mexico in 1940, but his legacy as a revolutionary thinker endures in the history of socialism. Leon Trotsky was a prominent Marxist revolutionary, born in 1879. He was instrumental in the Russian Revolution and the establishment of the Soviet Union, advocating for a global socialist movement. In addition to his political activities, Trotsky was a prolific writer and theorist, known for his concept of "permanent revolution," which challenged the idea of socialism being limited to individual nations. After being exiled due to political conflict with Joseph Stalin, Trotsky continued to write and criticize the Soviet regime, leaving a lasting impact on leftist ideologies until his assassination in 1940.