The Communist Party of Great Britain (CPGB) was the largest communist party in Great Britain between 1920 and 1991. Founded in 1920 through a merger of several smaller Marxist parties, the CPGB gained the support of many socialist organisations and trade unions following the political fallout of the First World War and the Russian October Revolution. Ideologically the CPGB was a socialist party organised upon Marxism–Leninist ideology, strongly opposed to British colonialism, sexual discrimination, and racial segregation. These beliefs led many leading anti-colonial revolutionaries, feminists, and anti-fascist figures, to become closely associated with the party. Many prominent CPGB members became leaders of Britain's trade union movements, including Jessie Eden, Abraham Lazarus, Ken Gill,