the grand rooms for which they were intended rather than following a chronological sequence, or arranged according to school of art. The finest rooms were decorated by Pietro da Cortona in the high baroque style. Initially Cortona frescoed a small room on the piano nobile called the Sala della Stufa with a series depicting the Four Ages of Man which were very well received; the Age of Gold and Age of Silver were painted in 1637, followed in 1641 by the Age of Bronze and Age of Iron. They are regarded among his masterpieces. The artist was subsequently asked to fresco the grand ducal reception rooms; a suite of five rooms at the front of the palazzo. In these five Planetary Rooms, the hierarchical sequence of the deities is based on Ptolomeic cosmology; Venus, Apollo, Mars, Jupiter (the Medici Throne room) and Saturn, but minus Mercury and the Moon which should have come before Venus. These highly ornate ceilings with frescoes and elaborate stucco work essentially celebrate the Medici lineage and the bestowal of virtuous leadership. Cortona left Florence in 1647, and his pupil and collaborator, Ciro Ferri, completed the cycle by the 1660s. They were to inspire the later Planet Rooms at Louis XIV's Versailles, designed by Le Brun. The collection was first opened to the public in the late 18th century, albeit rather reluctantly, by Grand Duke Leopold, Tuscany's first enlightened ruler, keen to obtain popularity after the demise of the Medici. Rooms of Palatine Gallery The Palatine Gallery has 28 rooms, among them: Room of Castagnoli: named after the painter of the ceiling frescoes. In this room are exposed Portraits of the Medici and Lorraine ruling families, and the Table of the Muses, a masterwork of stone-inlaid table realized by the Opificio delle Pietre Dure between 1837 and 1851. Room of the Ark: contains a painting by Giovan Battista Caracciolo (17th century). In 1816, the ceiling was frescoed by Luigi Ademollo with Transportation of the Ark of the Covenant Containing the Tablets of the Law. Room of Psyche: was named after ceiling frescoes by Giuseppe Collignon; it contains paintings by Salvator Rosa from 1640–1650. Hall of Poccetti: The frescoes on the vault were once ascribed to Bernardino Poccetti, but now attributed to Matteo Rosselli. In the center of the hall is a table (1716) commissioned by Cosimo III. In the hall are also some works by Rubens