Kullervo, son of Kalervo, is perhaps the darkest and most tragic of all J.R.R. Tolkien’s characters. ‘Hapless Kullervo’, as Tolkien called him, is a luckless orphan boy with supernatural powers and a tragic destiny. Brought up in the homestead of the dark magician Untamo, who killed his father, kidnapped his mother, and who tries three times to kill him when still a boy, Kullervo is alone save for the love of his twin sister, Wanona, and guarded by the magical powers of the black dog, Musti. When Kullervo is sold into slavery he swears revenge on the magician, but he will learn that even at the point of vengeance there is no escape from the cruellest of fates. Tolkien wrote that The Story of Kullervo was ‘the germ of my attempt to write legends of my own’, and was ‘a major matter in the legends of the First Age’; his Kullervo was the ancestor of Turin Turambar, tragic incestuous hero of The Silmarillion. In addition to being a powerful story in its own right, The Story of Kullervo, published here with the author’s drafts, notes and lecture-essays on its source-work, The Kalevala, is a foundation stone in the structure of Tolkien’s invented world.