The Chronicles of Narnia (although we do not learn their surname until "The Voyage of the Dawn Treader"), and eventually become Kings and Queens of Narnia reigning as a tetrarchy. Although introduced in the series as children, the siblings grow up into adults while reigning in Narnia. They go back to being children once they get back to their own world, but feature as adults in "The Horse and His Boy" during their Narnian reign. All four appear in "The Lion, the Witch, and the Wardrobe" and "Prince Caspian"; in the latter, however, Aslan tells Peter and Susan that they will not return, as
The Chronicles of Narnia song "Further Up, Further In" from the album "Room to Roam" by The Waterboys is heavily influenced by "The Chronicles of Narnia", with the title coming from a passage in "The Last Battle". C. S. Lewis is acknowledged in the liner notes as an influence. A convert to Christianity in later life, Lewis had authored a number of works on Christian apologetics and other literature with Christian-based themes before writing the "Narnia" books. The character Aslan is widely accepted by literary academia as being based on Jesus Christ. Lewis did not initially plan to incorporate Christian theological concepts into his