Trotsky was a key figure in the Bolshevik seizure of power in Russia, second only to Vladimir Lenin in the early stages of Soviet communist rule. But he lost out to Joseph Stalin in the power struggle that followed Lenin's death, and was assassinated while in exile.
Trotsky was born Lev Davidovich Bronstein on 7 November 1879 in Yanovka, Ukraine, then part of Russia. His father was a prosperous Jewish farmer. Trotsky became involved in underground activities as a teenager. He was soon arrested, jailed and exiled to Siberia where he joined the Social Democratic Party. Eventually, he escaped Siberia and spent the majority of the next 15 years abroad, including a spell in London.
In 1903, the Social Democrats split. While Lenin assumed leadership of the 'Bolshevik' (majority) faction, Trotsky became a member of the 'Menshevik' (minority) faction and developed his theory of 'permanent revolution'. After the outbreak of revolution in Petrograd in February 1917, he made his way back to Russia. Despite previous disagreements with Lenin, Trotsky joined the Bolsheviks and played a decisive role in the communist take-over of power in the same year. His first post in the new government was as foreign commissar, where he found himself negotiating peace terms with Germany. He was then made war commissar and in this capacity, built up the Red Army which prevailed against the White Russian forces in the civil war. Thus Trotsky played a crucial role in keeping the Bolshevik regime alive. He saw himself as Lenin's heir-apparent, but his intellectual arrogance made him few friends, and his Jewish heritage may also have worked against him. When Lenin fell ill and died, Trotsky was easily outmanoeuvred by Stalin. In 1927, he was thrown out of the party. Internal and then foreign exile followed, but Trotsky continued to write and to criticise Stalin.
Trotsky settled in Mexico in 1936. On 20 August 1940, an assassin called Ramon Mercader, acting on Stalin's orders, stabbed Trotsky with an ice pick, fatally wounding him. He died the next day.