Leon Trotsky (1879-1940) was, alongside Lenin, one of the two greatest Marxists of the twentieth century. His whole life was entirely devoted to the cause of the working class and international socialism. His role in the October Revolution is universally recognised. After Lenin’s death in 1924, Trotsky led the struggle against the bureaucratic degeneration of the Soviet State – a fight that Lenin had already begun from his death-bed. Thereafter, Trotsky alone continued to defend the revolutionary, democratic and international traditions of October. He alone provided a scientific Marxist analysis of the bureaucratic degeneration of the Russian Revolution in works like The Revolution Betrayed, In Defence of Marxism and Stalin. His writings of the period 1930-40 provide us with a veritable treasure-house of Marxist theory, dealing not only with the immediate problems of the international labour movement (the Chinese revolution, the rise of Hitler in Germany, the Spanish Civil War), but of all manner of artistic, philosophical and cultural questions.