The Hôtel Lambert () is a hôtel particulier, a grand mansion townhouse, on the Quai Anjou on the eastern tip of the Île Saint-Louis, in the 4th arrondissement of Paris. In the 19th century, the name Hôtel Lambert also came to designate a political faction of Polish exiles associated with Prince Adam Jerzy Czartoryski, who had purchased the Hôtel Lambert. Architectural history The house, on an irregular site at the tip of the Île Saint-Louis in the heart of Paris, was designed by architect Louis Le Vau. It was built between 1640 and 1644, originally for the financier Jean-Baptiste Lambert (d. 1644) and continued by his younger brother Nicolas Lambert, later president of the Chambre des Comptes. For Nicolas Lambert, the interiors were decorated by Charles Le Brun, François Perrier, and Eustache Le Sueur, producing one of the finest, most-innovative, and iconographically coherent examples of mid-17th-century domestic architecture and decorative painting in France. The entrance gives onto the central square courtyard, around which the hôtel was built. A wing extends to the right at the rear, embracing a walled garden. At the same time, Louis Le Vau constructed a residence for himself adjacent to the Hôtel Lambert. He lived there between 1642 and 1650. It was where all of his children were born and his mother died. After the architect's own death in 1670, his hôtel was bought by the La Haye family, who owned the other residence as well. Both buildings were then joined and their façades combined. Both painters worked on the internal decoration for almost five years, producing the gallant allegories of Le Brun's grand Galerie d'Hercule (still in situ, but heavily damaged in the 2013 fire described below) and the small Cabinet des Muses, with five canvases by Le Sueur that were purchased for the royal collection (now in the Louvre) and the earlier ensemble, the Cabinet de l'Amour, which in its original configuration featured an alcove for a canopied bed upon which the lady of the house would receive visitors, according to the custom of the day. Significantly the alcove was eliminated about 1703. All the ensembles featured themes of love and marriage. However, the paintings have since been dispersed. In the 1740s, the Marquise du Châtelet and Voltaire, her lover, used the Hôtel Lambert as their Paris residence when not at her country estate in Cirey. The marquise was famed for her salon there.