"The Legend of Sigurd and Gudrun," a thorough reworking in verse of old Norse epics that predates Tolkien's writing of "The Hobbit" and "The Lord of the Rings" trilogy, will be published in May by Houghton Mifflin Harcourt.
According to Houghton, the book will include an introduction by Tolkien and notes by his son, Christopher Tolkien.
J.R.R. Tolkien, whose fantasy novels have sold millions of copies, died in 1973. "The Legend of Sigurd and Gudrun" was written in the 1920s and '30s, when the author was teaching at Oxford University.