French architect, grandson of Jules Hardouin-Mansart. He became Architecte du Roi in 1742. His domestic designs include the Maison des Dames de Saint-Chaumont (1734) and the Hôtel Mansart de Sagonne (1743), both in Paris, both of which were essentially Rococo in style. His masterpiece is the elegant Cathedral Church of St-Louis, Versailles (1743–54), with its noble cupola and assured architectural enrichment. He also designed a hospital at Marseilles (1753). Given to high living, he eventually fled from France and may have settled in Lisbon, Portugal, after the earthquake of 1755.
Gallet (1972);Kalnein & Levey (1972);Jane Turner (1996)