Diana entdeckt den Fehler der Calisto

Juan Bautista Martínez del Mazo was Velázquez's son-in-law and closest studio assistant, eventually inheriting his position as court painter to Philip IV. This 1634 mythological work — Diana discovering Callisto's pregnancy — comes from early in his career, when he was working within Velázquez's direct orbit. The subject derives from Ovid's Metamorphoses and was a popular vehicle for female nude figure painting within the acceptable frame of classical mythology.

Diana and her nymphs react in varying degrees of shock and disgust upon discovering Callisto's transgression. Del Mazo structures the scene in a woodland setting with the nude figure of Callisto as the compositional center, following the Venetian tradition of figure-in-landscape for mythological subjects.