Château des Boulayes

Well-connected with a wealthy clientele of financiers, Nicolas-Claude Girardin built between 1777 and 1779 for the Genoese banker Octave-Pie Giambone the building on rue de Bondy known today as the Hôtel de Rosanbo. Giambone had married Marie-Louise de Marny, one of Louis XV's mistresses at the Parc-aux-Cerfs. They had a daughter, Adélaïde Catherine (1766-1824), who married Claude François Jean Bélanger (or Bellanger) (1757-1830), a colonel, "sous lieutenant des Gardes du corps", a high dignitary of the King's Household, a very handsome man who was one of Mme du Barry's protégés. The latter inherited the seigneury of Les Boulayes from his aunt, Adélaïde Labouré-Pothenot, in 1784. The name of this land – variants: les Boulaies, les Boulets – refers to a place planted with birch trees. This land belonged in 1546 to André Maillard, a counsellor at the parliament. His successor, Charles Maillard, under Charles IX, married Madeleine de Marillac. In the 18th century, in 1700, we find M. de Berenghien, lieutenant general of the provinces of Champagne and Brie, co-seigneur of Les Boulayes with the Marquis de Ségur (†1737)[citation needed]. The Château des Boulayes then belonged to M. Lettré. Having comfortable financial means thanks to his wife's dowry, Bélanger commissioned Girardin to modernize the estate by destroying the old dwelling surrounded by moats to replace it with a fashionable château. Construction was carried out quickly, from July to December 1785. Bélanger emigrated during the Revolution; his château was confiscated and sold as national property.

The château is inspired by the Hôtel de Thun built in 1771 by Étienne-Louis Boullée in the Chaussée d'Antin.