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. It is a white parallelepiped with a ground floor surmounted by one upper floor, whose roof was originally supported by a light timber frame with small woods à la Philibert Delorme. The facades are formed by the uniform repetition of the same bay with a colossal order of Corinthian pilasters identical on all four sides. In total, there are 42 pilasters defining 38 bays: thirteen on the main facades and six on the side facades. The traditional emphasis in the center of the facades is reduced here to a meager projection defining a barely perceptible five-bay avant-corps, which was originally surmounted by a pediment. The openings are arched French windows on the ground floor and rectangular cross-windows on the first floor. The château has undergone few transformations. Nevertheless, in 1912, the original timber frame and pediments were removed and replaced by a flat Italian-style roof surrounded by a balustrade, in reference to the Grand Trianon, which made the elevations quite monotonous. Internally, part of the original decor has been preserved. According to Michel Gallet, "the most beautiful room is a dining room whose stoves, surmounted by statues inspired by antiquity, were supplied by the stove-maker Marentin."

The facades and roofs are listed in the supplementary inventory of historical monuments by decree of June 18, 1946. The Château des Boulayes is located within a site listed by decree of March 6, 1947.