Short answers, pulled from the story.
Vladimir Lenin, born Vladimir Ilyich Ulyanov, was a Russian revolutionary, politician and political theorist. He founded the Bolsheviks, led the October Revolution of 1917, and served as the first head of government of Soviet Russia and then the Soviet Union until his death in 1924.
Lenin embraced revolutionary socialist politics after his elder brother Aleksandr was executed in May 1887 for plotting to assassinate Tsar Alexander III. He was later expelled from Kazan University for joining student protests and exiled to the family estate at Kokushkino.
The split happened at the second Russian Social Democratic Labour Party Congress in London in July 1903. Lenin demanded strong central leadership while Julius Martov wanted members to act independently. Lenin's majority became the Bolsheviks and Martov's minority became the Mensheviks.
After the February Revolution of 1917, Lenin returned from Switzerland through wartime Germany, which permitted 32 Russian citizens to cross its territory by train. It was called a sealed carriage for political cover but was not truly sealed, and passengers even spent a night in Frankfurt before he reached Petrograd's Finland Station in April.
The Treaty of Brest-Litovsk, signed on the 3rd of March 1918, withdrew Russia from the First World War at enormous cost. It transferred 26% of the former empire's population, 37% of its agricultural harvest area, 28% of its industry, 26% of its railway tracks, and three-quarters of its coal and iron deposits to German control.
Lenin introduced the New Economic Policy in early 1921 to stabilise the economy after the famine of 1921 and the policy of war communism. It allowed some private enterprise, the reintroduction of the wage system, and let peasants sell produce on the open market while basic industry, transport and foreign trade stayed under state control.
Lenin suffered three debilitating strokes in 1922 and 1923 before his death in 1924. His death began a power struggle that ended in Joseph Stalin's rise to power, and Lenin became the subject of a pervasive personality cult within the Soviet Union until its dissolution in 1991.