A British-American historian and author, he is most famous for The Great Terror: Stalin's Purge of the Thirties (1968). His other scholarly works include Where Marx Went Wrong (1970) and Common Sense About Russia (1960).
He was the son of a British mother and an American father. He attended Magdalen College, Oxford, among other universities, and received advanced degrees in politics, philosophy, economics, and Soviet history.
He was a respected poet and a member of The Movement, a prominent British literary group.
He was divorced three times prior to his 1979 marriage to Elizabeth Neece Wingate.
He criticized philosopher Jean-Paul Sartre, among other intellectuals of his time, for turning a blind eye to the violence of Stalin's regime.