Francesco di Giorgio was a Sienese sculptor, painter, illuminator, architect, and military engineer. The precise function of this drawing is uncertain; it may record an idea for a tomb sculpture or a trompe-l'oeil painting. The foreshortened architectural perspective and the downward gaze of the figures suggest it was intended to be placed high on the wall of a chapel or nave. Portrayed with individualized features, the male figure in the center, who may be the patron, has been described as an unidentified humanist flanked by muses or the liberal arts holding books. It is also possible that this vellum sheet served as the frontispiece of a manuscript, specifically Francesco di Giorgio’s treatise on machines (Opusculum de architectura), made around 1475, whose illustrations resemble the present drawing. In this case, the male figure may be a portrait of the Sienese master himself.