The Duchess of Bourbon had been known for frivolity at the Court in Versailles, but by the 1720s she had had seven children and was widowed. The reputed lover of the Duchess, Armand de Madaillan de Lesparre, the Count of Lassy ("Comte de Lassay") proposed the site of the palace to her; he had purchased land next door along the Seine, and the two buildings were constructed at the same time. The parcel of land for the new palace was large, extending from the Seine to the rue de l'Université.