Comintern (COMmunist INTERNational) is the commonly given name for the Third International. It was formed on the initiative of Lenin and the Communist Party of Russia (Bolshevik), as they were of the opinion that the Second International had betrayed socialism by the support of its major sections for the First World War.

Founded in 1919 the Comintern would hold seven World Congresses, the last in 1935, until it was dissolved in 1943. Left communists today recognise only the first two congresses and the Trotskyist movement recognises the decisions of the first four only. But all seven traditionally form the bedrock of the mainstream Communist Parties.

Lenin had previously written of his disappointment in the way in which many European Social-Democrats had failed to speak out against World War I, and was particularly critical of individuals such as Kautsky and Ramsay MacDonald, disparagingly describing them as Social-Chauvinists.

This failure of the Second International Social-Democrats prompted the Bolsheviks to adopt the name Communist in place of Social-Democrat, and to convoke the Third International.

Central to the policy of Comintern was that Communist parties should be established across the world to aid the international Proletarian Revolution, and the idea of democratic centralism, which involved rigid control of the Communist Party from the centre.

Whilst Comintern was supposedly an international organisation, it was effectively controlled by the Soviet Union.

For a party to join the Comintern it had to accept 21 conditions. Some of these were:

  • To carry out propaganda in the countryside and cities in favour of proletarian revolution
  • To remove reformists and centrists from positions in the working class movement
  • To combine legal and illegal methods of working
  • To supervise the activities of any members in parliament
  • To denounce pacifism
  • To support colonial liberation movements
  • To ensure trade unions join the 'red' trade union international rather than the 'yellow' Amsterdam one.
  • To organise on the basis of democratic centralism and to have regular purges of membership
  • To support all existing Soviet republics
  • To revise its party programme with policies of the International
  • To accept all decisions of the Comintern as binding
  • To take the name 'Communist Party'
  • To expel all members who voted against any of the 21 conditions

In 1938 Leon Trotsky formed the Fourth International. See also: List of Communist Parties, List of members of the Comintern