At the beginning of the 17th century, painters in Paris were considered primarily as artisans, not as artists. Like other artisans, they had their own professional guild, the "imagiers-paintres", which also included engravers, illuminators and sculptors. Under the guild rules approved by the Provost of Paris in 1391, and renewed in 1619, they were required to use good-quality paint, and they were protected against foreign competition; it was expressly forbidden to import works of art from Flanders, Germany or elsewhere in Europe except during the period of the Fair of Saint-Germain and other major trade fairs. It was also forbidden by a 1639 ordinance to paint portraits of nude men or women with "postures lascivious and dishonest, and other grotesques which injure their chastity." Beginning in 1609, the Louvre Galerie was created, where painters, sculptors, and artisans lived and established their workshops. Under Louis XIV, with many new commissions for the palace in Versailles and the town houses of the nobility in Paris, the profession grew. The number of masters in the guild increased from 275 in 1672 to 552 in 1697. In addition to the guild, in 1391 the majority of painters belonged to the Académie de Saint-Luc, a professional and fraternal association. In 1648, many of the most successful and ambitious painters and sculptors, who wanted recognition as artists and not simply craftsmen, joined together to found another group, the Académie de peinture et de sculpture. In 1667, the Académie organized its first official exposition of works of art of its members. These exhibitions were held every two years, opening on August 25, the day of Saint-Louis. They were first held in the court of the Palais-Royal, then in the Grand Gallery of the Louvre, and then, beginning in 1699, in the Salon Carré of the Louvre, which gave the event the name "Salon". It became the chief avenue for French artists to achieve recognition and success. The most famous painter to work in Paris during the period was Peter Paul Rubens, who came to the city in 1622 to paint a series of murals for the Luxembourg Palace which now are in the Louvre. Other painters who achieved fame in Paris early in the century were Claude Vignon, Nicolas Poussin, Philippe de Champagne, Simon Vouet, and Eustache Le Sueur.