<onlyinclude> The Oz books form a book series that begins with The Wonderful Wizard of Oz (1900) and relate the fictional history of the Land of Oz. Oz was created by author L. Frank Baum, who went on to write fourteen full-length Oz books. All of the books are in the public domain in the United States. Even while he was alive, Baum was styled as "the Royal Historian of Oz" to emphasize the concept that Oz is an actual place. The illusion created was that characters such as Dorothy and Princess Ozma related their adventures in Oz to Baum themselves, by means of wireless telegraph.