The book is a study of the life and work of the famous Golden Horde political and statesman Mamai. Over the course of centuries, an extremely negative image of him, the image of the so-called anti-hero of history, has been formed in historiography. The author of the book tries to restore the real biography of Mamai, highlight some of its controversial aspects (including the origin of Mamai, his status, relations with khans and foreign rulers), and also trace the process of creating such a negative image of this figure over several centuries.