The Communist Party of the Soviet Union was the ruling party of the Soviet Union for all of its existence. Originally, the party was part of the Russian Social Democratic Labour Party, until it split into two factions, with the 'Bolshevik' faction led by Vladimir Lenin ultimately turning into the CPSU. After Lenin's death in 1924, and Leon Trotsky assuming the title of Premier, the Communist Party started to fall into factionalism. Those loyal to Trotsky became the 'Internationalists,' while hardliners and those still loyal to the ideas of Stalin became the 'Nationalists.' There was also a smaller, but still prominent, faction known as the 'Councilists,' which opposed the growing bureaucracy of the Soviet state and supported trade unions and council democracy.