Head of a bishop [from 'The Coronation of Charlemagne']

A photograph of a drawing by Carlo Maratti currently in the Royal Library, Windsor Castle (RCIN 904246). The drawing reproduces the head of a bishop, depicted at lower right in the fresco of 'The Coronation of Charlemagne', painted by Raphael and his workshop in the Stanza dell'Incendio in the Vatican.