sentences:  The stories in "The Book of Lost Tales" employ the narrative device of a mariner named Eriol (in later versions, Ælfwine) who finds the island of Tol Eressëa, where the Elves live; and the Elves tell him their history.Tolkien envisaged Ælfwine as an Anglo-Saxon who visited and befriended the elves and acted as the source of later mythology.Thus, he is given as the author of the various translations in Old English that appear in "The History of Middle-earth" series.