This picture closely resembles the portraits of Francesco and Mattias di Cosimo de' Medici, brothers of the present sitter, in the Uffizi, Florence (inv. 1890, nos. 2456 and 2459 respectively). All of these portraits are the work of two Florentine painters, the brothers Domenico and Valore Casini. Their workshop account book mentions two series of portraits of Grand Duke Cosimo II de' Medici's sons as children (for the account book see L. Goldenberg Stoppato and M. P. Mannini, 'Domenico e Valore Casini, ritrattisti: un giornale di bottega ritrovato', in the collection of essays Scritti per l'Istituto Germanico di Storia dell'Arte di Firenze, Florence, 1997, pp. 349-354).
We are grateful to Dr. Lisa Goldenberg Stoppato for the attribution to Domenico and Valore Casini, and for her assistance in cataloguing this lot. The series of portraits of Cosimo II's children are to be cited in a forthcoming article by Dr. Goldenberg Stoppato to be published in Paragone.