In a note on the mount, Michael Hirst observed that this is Perino del Vaga´s copy after one of the figure groups in Polidoro da Caravaggio´s now destroyed fresco, painted on the facade of the Casino del Buffalo, Rome. The appearance of the decoration survives in engravings as well as in numerous drawn copies, such as this (Ravelli, 1978, pp. 327-333, nos. 567-579). The Prado study is of particular interest since it shows Perino´s admiration for the inventiveness of a fellow pupil of Raphael and, as Michael Hirst pointed out, may have been made soon after the fresco decoration had been completed and before both artists fled Rome in the wake of the disastrous sacking of the city by imperial troops in 1527. In the opinion of Leone de Castris, Perino´s copy was probably carried out some ten years later when Perino returned to Rome. From the point of view of Perino´s drawing style, this second hypothesis for the dating seems more likely, since the handling matches precisely that of another drawing in the Prado connected with a commission Perino undertook in Rome in 1538-1539.

Phineus was Perseus´s rival for the love of the beautiful maiden Andromeda, whom Perseus had found chained to a rock on the seashore, after she had been taken there as an offering to a wicked sea-monster. Perseus fell in love with her at first sight and rescued her by flying over the monster´s head on his winged horse, flourishing the Gorgon´s head into its line of vision. The monster was instantly turned into stone, allowing Perseus to free Andromeda from her shackles. At the feast held to celebrate the subsequent wedding of Perseus and Andromeda, the disappointed Phineus, accompanied by his followers, interrupted the proceedings. Perseus quelled the ensuing fracas by taking again the Gorgon´s head and thrusting it at his opponents, who were instantaneously transformed into stone.

Other drawn copies by Perino after Polidoro´s Roman facade decorations are in the collection of the Palazzo Abatellis in Palermo, this time after the ornamental vases on the front of the Palazzo Milesi (inv. nos. 5237/14 and 15; Palermo, 1995-1996, nos. 15 and 16). Perino not only copied from the work of Polidoro but was in the habit of copying the work of other successful contemporaries, including Jacopino del Conte´s Preaching of the Baptist and Francesco Salviati´s Visitation, both painted in 1538 in the newly decorated Oratory of S. Giovanni Decollato, in Rome (Text drawn from Turner, N.: From Michelangelo to Annibale Carracci. A century of Italian drawings from the Prado, Art Services International-Museo Nacional del Prado, 2008, p. 80).