Tolkien's legendarium is the body of J. R. R. Tolkien's mythopoeic writing, unpublished in his lifetime, that forms the background to his The Lord of the Rings, and which his son Christopher summarized in his compilation of The Silmarillion and documented in his 12-volume series The History of Middle-earth. The legendarium's origins reach back to 1914, when Tolkien began writing poems and story sketches, drawing maps, and inventing languages and names as a private project to create a mythology for England. The earliest story, "The Voyage of Earendel, the Evening Star", is from 1914; he revised and rewrote the legendarium stories for most of his adult life.