Complex sentence: They are based on the 1937 novel "The Hobbit" by J. R. R Tolkien, although portions of the trilogy are also adapted from the appendices to "The Return of the King".
Split into simpler sentences: They are based on the 1937 novel "The Hobbit" by J. R. R Tolkien. Portions of the trilogy are also adapted from the appendices to "The Return of the King".