Luca Giordano, 'The Cave of Eternity', early 1680s

This group of ten paintings was made by Giordano as a series of detailed oil studies (or modelli) for the ceiling frescoes in the Palazzo Medici Riccardi in Florence. Begun in 1682 and completed in 1685, the frescoes are among Giordano’s finest achievements and appear to have been painted ‘a secco’ – that is, on dry rather than fresh (‘a fresco’) plaster. The modelli were originally part of a set of 12 (the other two are in private collections). Nine of them relate to the ceiling of the highly ornate Galleria and the tenth – the Allegory of Divine Wisdom – is associated with the ceiling of the adjacent Library.

Giordano seems to have produced preliminary oil sketches based on drawings, and then worked up more finished oil sketches to clarify his design. It was probably these that Giordano presented for approval to his client, the Marquess Francesco Riccardi (1648–1719), so that any required changes could be discussed before the frescoes were executed (some differences can be seen when we compare the modelli with the final frescoes). Others have suggested that these ten modelli were painted after the frescoes were completed, as ricordi (or visual records). Contemporary documents do make clear that the modelli were valued as finished works in their own right. The ten canvases in the National Gallery still have the original carved and gilded frames made for them in Florence in the 1680s, as they were clearly hung and on display at the Palazzo Medici Riccardi (where they remained until the early nineteenth century).

The Palazzo, which had originally been built by Cosimo de' Medici in the mid-fifteenth century, was bought in 1659 by the Medici’s friends and allies, the fabulously wealthy Riccardi family. They doubled the size of the original building, and the showpiece of the new extension on the west side of the palace was a splendid Galleria on the first floor, with a barrel-vaulted gallery and heavily gilded stucco decorations. Flooded with light from the south- and west-facing windows that line two of its sides, this room was intended to house a precious collection of antiquities and to function as a public reception room.

The frescoes in the Galleria were designed not only to impress Florentine society, but to flatter the Medici specifically; they were still the most powerful family in the city. Giordano’s adviser for the iconography of the ceiling was Alessandro Segni, a man of letters who had been Francesco Riccardi’s tutor and travelling companion. Between them, the three men devised the continuous frieze of interconnected scenes which runs around the lower part of the ceiling. The overall theme in the Galleria is the elevation of mankind through Wisdom and Virtue, using allegorical and mythological figures to represent different strengths and traits. It culminates in a centrepiece that presents the Medici family, elevated to the company of the gods, as the paradigm and embodiment of both of these qualities. Other themes, including particular virtues, the four elements, the cycle of life and death and the regenerative power of nature, are also woven into the visual narrative.

At the two short ends of the room are scenes representing human life (The Cave of Eternity) and industry and the arts (Minerva as Protectress of the Arts and Sciences). On the long sides are mythological figures and allusions to classical myths and legends. The Rape of Proserpine incorporates scenes of death, judgement, punishment and the afterlife, while the adjacent scene celebrates agriculture and fecundity. On the opposite long side of the ceiling, the modelli for which are in two different private collections, the triumph of the Roman gods Bacchus, Neptune and Amphitrite adjoins the Death of Adonis. In the corners of the Galleria are allegories of the four Cardinal Virtues: Fortitude, Justice, Prudence and Temperance.

Understanding the Galleria’s ceiling is not just about decoding the allegories, which are often complex and imprecise and are always open to different interpretations. Giordano’s great achievement in the frescoes was to fuse all these parts together into a vast swirling whole, remarkable for its lightness, transparency and sheer visual brilliance – vast areas of the ceiling are given over to blue sky and translucent white clouds. Though the modelli are darker, more static, on a smaller scale and divided into separate scenes, they are crucial to understanding the decorative scheme’s artistic development.