Karel van Mander famously characterized Goltzius as a "Proteus or Vertumnus of art", a turn of phrase that has been taken to refer to his virtuosic skill at engraving in the styles of all the best masters. Often overlooked is the fact that Goltzius also conspicuously exercised his abilities as an iconographer in his early career as a print publisher. Between 1582, when he started his Haarlem print studio, and 1590, when he departed for Italy, Goltzius used classical rhetorical methods to construct innovative compositions. He thus promoted not only his skillful hand, but also his inventive and resourceful mind. This thesis considers Goltzius's intellectual circles in Haarlem during this critical professional period, presents several case studies of his inventive iconographies, and concludes with two new interpretations of mythological artworks based on the artist's rarely-acknowledged use of iconographic manuals and emblem books.