Abstract:Andrea Palladio’s I quattro libri dell’architettura is one of the most influential books on architecture ever written. It was reprinted, republished, and translated several times, illustrated with woodcuts after the author’s own drawings. It gives evidence of Palladio’s famous architectural theory and practice. The frontispiece was used as a condensed rhetorical narrative, and the different editions varied considerably with regard to their philosophical content. This paper explores the iconology and iconography of the frontispiece adorning its first edition in 1570, then makes conjectures about the implied symmetry and the absence of Palladio’s portrait, with the aim to understand the perception of the book and the role of virtue (virtus) as presented by the author, the publisher, and the engraver. Finally, by comparing the original frontispiece with that of Colen Campbell’s English translation, the paper demonstrates how and why the Regina Virtus was replaced by an image of the architect, and how eventually the Quattro libri was transformed from a method (of acting according to ideas articulated in the book) to a model (where style or design parameters were fixed).