This is the first biography in any language of "Comrade Prince" D. S. Mirsky, who uniquely participated in three distinctive episodes of modern European culture. In late imperial St. Petersburg he was a poet, a student of Oriental languages and ancient history, and also a Guards officer. After fighting in World War I and the Russian Civil War, Mirsky emigrated, taught at London University, and became a literary critic and historian, writing prolifically in English, and also in Russian as a leading member of the Eurasian movement centered in Paris. His closest literary relationships were with Marina Tsvetaeva and Aleksei Remizov, and later with Maksim Gorky. In 1926-7 he published A History of Russian Literature, written in English, which remains the standard introduction to the subject. While in London he lived in Bloomsbury and knew the Woolfs; he also knew T. S. Eliot, and was the first Russian critic to write about him. Mirsky became a Communist in 1931 and returned to Stalin's Moscow the following year, becoming a prominent Soviet critic, and in particular championing Boris Pasternak. In 1937 he was arrested, and died in the Gulag. This biography draws on much unpublished material, including Mirsky's NKVD files.