Jacob-David Duval (Moscow 1768-1844 Geneva), son of Louis-David Duval and his wife Rosa, continued the business of his father as a jeweller in St-Petersburg. He supplied both Catherine the Great and her son Tsar Paul I and was appointed Jeweller of the Crown with the rank of a civil colonel by the latter. He married Bonne Alexandre in 1790 and returned to Geneva in 1803. It is interesting to note that he was the brother of Jeanne-Louise Duval who married the celebrated enameller Nicolas Soret in 1792.