Josef Stalin exercised supreme power in the Soviet Union from 1929 until his death in 1953. During that quarter-century, by Oleg Khlevniuk's estimate, he caused the imprisonment and execution of no fewer than a million Soviet citizens per year. Millions more were victims of famine directly resulting from Stalin's policies. What drove him toward such ruthlessness? This essential biography, by the author most deeply familiar with the vast archives of the Soviet era, offers an unprecedented, fine-grained portrait of Stalin the man and dictator. Without mythologizing Stalin as either benevolent or an evil genius, Khlevniuk resolves numerous controversies about specific events in the dictator's life while assembling many hundreds of previously unknown letters, memos, reports, and diaries into a comprehensive, compelling narrative of a life that altered the course of world history.

In brief, revealing prologues to each chapter, Khlevniuk takes his reader into Stalin's...