The Royal Book of Oz is the fifteenth in the series of Oz books. It finds the Scarecrow upset when Professor Woggle-bug tells him that he has no family, so he goes back to the corn-field where Dorothy Gale found him to trace his roots. The Scarecrow discovers that he was the King of the Silver Islands, a quasi-Chinese kingdom located underground beneath the Munchkin region of Oz.

Lyman Frank Baum (1856 - 1919), better known by his pen name L. Frank Baum, was an American author chiefly known for his children's books, particularly The Wonderful Wizard of Oz. He wrote thirteen novel sequels, nine other fantasy novels and a host of other works (55 novels in total, plus four "lost works", 83 short stories, over 200 poems, an unknown number of scripts and many miscellaneous writings) and made numerous attempts to bring his works to the stage and screen. His works anticipated such century-later commonplaces as television, augmented reality, laptop computers (The Master Key), wireless telephones (Tik-Tok of Oz), women in high risk, action-heavy occupations (Mary Louise in the Country) and the ubiquity of advertising on clothing (Aunt Jane's Nieces at Work).