Pierre Contant d'Ivry (11 May 1698 in Ivry-sur-Seine – 1 October 1777 in Paris), was a French architect and designer working in a chaste and sober Rococo style and in the goût grec phase of early Neoclassicism. Early career An Architecte du Roi from 1728, he spent his career working for the French Crown and for an aristocratic private clientele: the contrôleur-général des finances Machault d'Arnouville, the princes de Soubise and de Croÿ, and baron Bernstorff, the Danish ambassador. Though he was not formally received into the Académie royale d'architecture until 1751, he was the architect attached to Louis François I de Bourbon, prince de Conti, between 1737 and 1749. He was replaced in this position by Jean-Baptiste Courtonne. Palais-Royal Later Contant d'Ivry worked for Louis-Philippe, duc d'Orléans, for whom he transformed interiors of the Palais-Royal, Paris, in 1754, designs that were widely admired and published by Diderot and d'Alembert in the Encyclopédie, 1762, where Jacques-François Blondel praised their "correct middle pathway between two excesses, that of the heavy weight of our ancients and that of frivolity". Surviving examples include the dining room of the Duchesse d'Orléans (now the Salle du Tribunal des Conflits of the Conseil d'État), which is in a neo-classical style with pilasters, and another of her rooms (now the Salle des Finances), in which his surviving decoration of the ceiling and door panels is lighter and more reminiscent of the earlier French Regency period. Contant d'Ivry was also responsible for the exteriors of the northern part of the east wing (now on the Rue de Valois), the avant corps of which, "with its giant balcony brackets and rather inventive detailing, combines Rococo-style decorative charm with a certain Classical solidity in its massing." In 1763 a fire which started in the east wing in the opera house, the Salle du Palais-Royal, destroyed not only the theatre but also the adjoining sections of the palace. While the municipality of Paris was responsible for the opera house and hired its own architect, Pierre-Louis Moreau-Desproux, who also designed the new facades on the Rue Saint-Honoré side of the building, Louis Philippe engaged Contant d'Ivry, who designed the interiors of the reconstructed corps de logis, the facades of the Cour d'Honneur (on the garden side), and a grand staircase, the "splendid escalier d'honneur, [which] with its domed covering and dramatic curved descent, is justly famous." Église de la Madeleine In 1757,