Damiano Mazza, 'The Rape of Ganymede', about 1575

A huge black eagle soars into the clouds with a naked youth clutched in its talons. The boy, grasping his bow and the eagle’s black feathers, struggles to escape. The painting illustrates the rape of Ganymede. In Greek mythology, the beautiful shepherd boy Ganymede was carried away by Jupiter in the form of an eagle to the home of the gods on Mount Olympus and made their cupbearer. The sole of the boy’s right foot is lit from below and his scarf floats below the powerful beating wings of the bird, creating the impression that the scene is taking place high up in the air.

The Rape of Ganymede was painted for Francesco Assonica, a lawyer from Bergamo, who worked in Padua and Venice and acted for Titian in 1550 and 1566. Although it has been assumed that the picture reflects the sexual orientation of its patron, this is unlikely. The rape of Ganymede was a popular subject for ceiling paintings, interpreted as an example of divine favour, and was often paired with the fall of Phaeton – an example of Jupiter’s wrath – as both scenes take place in the air. The picture was probably painted to decorate ceiling of the belvedere (open-sided rooftop terrace) of Assonica’s house in Padua. Titian may have recommended the Paduan Mazza, who is described in seventeenth-century sources as his pupil.

The painting was originally shaped as an irregular octagon, but canvas was added in the early eighteenth century to make it into a rectangle. Mazza’s composition is one of many experiments made by Venetian artists to emulate Giulio Romano’s daring ceiling painting of the Fall of Phaeton of 1527–8 in the Palazzo del Te in Mantua, in which Phaeton and his chariot tumble from the cloudy heavens.

The blue smalt – a pigment that consists of ground cobalt blue glass – in the sky of Mazza’s picture has discoloured to a warm grey. Prussian blue, a pigment that first came into use in the eighteenth century, has been painted on top of it.

The impact of Mazza’s painting has been reduced by its conversion from a ceiling octagon to a rectangular gallery picture. Originally, the wings would have been cut by the frame, and the boy’s left foot and the bird’s beak would have only just been contained by it. This would have greatly enhanced the drama of the composition.

Titian used suspended models made of wood, clay and wax to work out the foreshortened poses for his paintings. Mazza also adopted this practice and, unusually, the bronze figure he used here has survived (Barthélemy Prieur, Statue of Cupid, about 1560, Bronze, Private collection).

From 1664 to 1887 the painting was catalogued as by Titian. After that, it was recognised as by Mazza but still thought to be a copy of an original painting by Titian. The picture was painted quickly and there are lots of areas of over-painting where the artist changed his mind. This makes it very unlikely to be a copy of another picture, as Mazza was clearly making adjustments to the composition as he painted.