The attribution was first advanced by Herwarth Röttgen. This drawing would appear to be a study for the head of the woman in the foreground of the Fall of Simon Magus painted on slate in 1602 for Saint Peter's, Rome. The painting for which he was awarded the title Cavaliere di Cristo by Pope Clement VIII is now in store because of its poor condition. The composition is also known through two copies after the picture in the Louvre, F. Viatte, Dessins Toscans XVI^e-XVIII^e Siècle, Paris, 1988, I, nos. 553-4, illustrated. The picture was Vanni's most prestigious Roman commission and Riedl traced 25 preparatory studies for the commission in the Uffizi and and the Biblioteca Comunale di Siena, P.A. Riedl, Disegni del Barocceschi Senesi, Florence, 1976, nos. 50-6, illustrated