The Bolshevik revolutionary Leo Trotsky had an entirely negative judgement about the London Bureau: ‘A very deceptive community of interests without any content, without any perspective, without any future’.1 The Black Caribbean revolutionary George Padmore came to a very different opinion: the London Bureau meant ‘hope and courage to the oppressed coloured races’.2 The London Bureau was the short name used for an international organization of independent socialist parties existing between 1930 and 1939. Its secretariat was located most of the time in London, hence the name London Bureau. Founded August 1930 as the International Association, in 1933 it became the International Committee of Independent, Left Socialist Revolutionary Parties. In 1935 it changed its name to the International Bureau for Revolutionary Socialist Unity. The Bureau dissolved in 1939 to be succeeded by the International Revolutionary Marxist Centre (IRMC).