D'Holbach wrote nothing of his childhood though it is known he was raised in Paris by his uncle Franz Adam Holbach, (or "Adam François d'Holbach" or "Messire François-Adam, Baron d'Holbach, Seigneur de Heeze, Leende et autres Lieux") (approx. 1675–1753), who had become a millionaire by speculating on the Paris stock-exchange. With his financial support, d'Holbach attended the Leiden University from 1744 to 1748. Here he became friends with John Wilkes. Later he went on to marry his second cousin, Basile-Geneviève d'Aine (1728–1754), on 11 December 1750. In 1753, a son was born, Francois Nicholas who left France before his father died. In 1753 both d'Holbach's uncle and father died, leaving him with an enormous inheritance, such as Heeze Castle, "Kasteel Heeze te Heeze".