Before creating the illustrations that would help define the look of Baum's characters in countless film and play adaptations for decades to come, Denslow and Baum had success with another collaboration, Father Goose: His Book. After fighting the publisher to include color illustrations paid off with big sales, Denslow was cleared for a much more ambitious treatment of The Wonderful Wizard of Oz. He worked closely with Baum to work out costumes, landscapes, and other details that expanded on the original text, putting Denslow in more of a co-creator role which granted him partial ownership of a very, very lucrative copyright. Now flush with money, Denslow would make a bold, and ultimately ill-fated, decision to buy an island off Bermuda to build a castle and declare himself King Denslow I.