Who is Vladimir Ilyich Lenin from The Gulag Archipelago, 1918-1956 and what is their importance?

Vladimir Ilyich Lenin was a Russian revolutionary, leader of the October (Bolshevik) Revolution, and first head of the USSR, Lenin is sometimes referred to by his birth surname, Ulyanov, and by his patronymic, Ilyich. Solzhenitsyn never treats Lenin directly, but refers to events in his turbulent life, like his eldest brother's arrest and hanging for plotting to kill Tsar Alexander III, his imprisonment and light exile in Siberia, and travels in Russia and Europe. He alludes to Lenin's break with Social Democrats and split with the Second International. Elected to head the new Bolshevik government, he makes peace with Germany (Treaty of Brest-Litovsk), which sacrifices territory and remunerations, and is opposed by Social Revolutionaries (SRs) and other parties. Lenin begins a massive, bloody persecution, organizes the Cheka, and launches a "Red Terror." Solzhenitsyn alludes to unprecedented brutality of the Civil War, the extermination of the kulaks, War Communism, the famine of 1921, peasant uprisings, the Kronstadt revolt, and New Economic Policy (NEP). He refers to Lenin's first stroke in 1922, but not to his gradual decline or death.