During his short period of prominence, Trotsky's impact on the early Bolshevik regime- its birth, development and survival- can be boiled down to three main events in which he was the driving force, not Lenin. These events are the October revolution itself in late 1917, his role as Commissar for Foreign Affairs at the Treaty of Brest-Litovsk (the peace negotiations with Germany in the winter of 1917-18), and his vital role as Commissar for War during the Russian Civil War from 1917-22. Following victory in the war and soon after, the death of Lenin, Trotsky was quickly outmaneuvered by Stalin, who turned the Soviet elite against him, and Trotsky was expelled from the party by 1927.

Lenin was not in Russia during the lead-up to the Bolshevik revolution, and thus it was Trotsky who coordinated and gathered the Bolsheviks in the months prior to November 1917, after his release from prison in September. It was Trotsky who spearheaded Bolshevik preparations, such as the creation of the Military Revolutionary Committee. Trotsky also played an important role in motivating the party and its supporters using is talent for rhetoric, with Carr labelling him as "the greatest orator of the revolution". Trotsky coordinated the events of the 7th of November 1917, overthrowing the Provisional Government by storming the Tsar's Winter Palace in Petrograd. Had Trotsky not been there, and without Lenin as a unifying force in the lead-up to November, the revolution may have stalled or failed outright due to the lack of discipline and unity that Trotsky provided, highlighting the extent to which he influenced his times.

The first real examples of uniquely Trotskyist ideology having a significant effect on events in history were his attempts to cease hostilities with the Germans at Brest-Litovsk in the winter of 1917-18. Conforming with his ideology of "permanent revolution", Trotsky, as Commissar for Foreign Affairs, beleived that socialist revolution in Germany was imminent, and instead proposed an end to both hostilities and peace negotiations, simply to stop fighting without settlements. While the Germans wished to close the Eastern Front as well, they still held a significant superiority over Russia, and resumed hostilities in Februrary, eliciting Trotsky's acceptance of much harsher peace terms in March at the second round of talks. This is representative of Trotsky's flaws in dealing with such matters, where a lack of pragmatism from the "fanatical ideologue" as described by Volkogonov, came at a great cost to Russian territorial claims.

Trotsky's most important influence on his times was his role as Commissar for War and his subsequent leadership of the Red Army in the Civil War. The Bolshevik situation at the time looked grim, with an untrained army outnumbered five to one and surrounded on all sides by White forces. However, Trotsky took the initiative, actively shaping the course of the war by reforming the Red Army with standardised equipment, uniforms and ranks, and instilling a strong sense of ruthless discipline, evident in his quashing of the Kronstadt revolt in 1921. His travel by train to the front provided much-needed motivation, with Bradley describing it as a "unifying factor". Arguably Trotsky's actions in the Civil War were responsible for the survival of the Bolsheviks, perhaps his most significant influence on his times.

Sources: Webb, Ken: Leon Trotsky 1879-1940 Service, R., Trotsky: A Biography Volkogonov, D., Trotsky: The Eternal Revolutionary