The new movie Oz the Great and Powerful opens today in theaters nationwide. The backstory of the wizard is loosely based on the L. Frank Baum book The Wonderful Wizard of Oz. Baum went on to write 14 more books about Oz, because the public kept demanding more. An interesting fact I didn't know -one of his granddaughters was named after an Oz character!
Baum had a granddaughter named "Ozma," and his 11th Oz book, The Lost Princess of Oz (published 1917), was dedicated to her shortly after her birth. The story begins with the disappearance of Princess Ozma, the ruler of Oz.