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 underworld. There are several maps of the Narnian universe available, including what many consider the "official" one, a full-colour version published in 1972 by the books' illustrator, Pauline Baynes. This is currently out of print, although smaller copies can be found in the most recent HarperCollins 2006 hardcover edition of "The Chronicles of Narnia". Two other maps were produced as a result of the popularity of the 2005 film "". One, the "Rose Map of Narnia", is based loosely on Baynes' map and has Narnian trivia printed on the reverse. The other, made in a monochromatic, archaic style reminiscent of