Jacques de Beaufranchet was born in 1731. His sister Amable married Gilbert Antoine des Aix, "seigneur de Veygoux", and was mother to the famous General Desaix, who died at the Battle of Marengo in 1800. He was captain to the major's aide for the Beauvoisis regiment. He was killed in 1757 at the Battle of Rosbach, and left behind his wife " La belle Morphyse ", who was King Louis XV's mistress, and who he had married November 25, 1755. From certain memoires, the lady Marie-Louise O'Murphy de Boisfaily, known as "Morphyse", was born in Rouen, in Normandy, from an officer of the King of France, of Irish origin. Louis XV, had her married to Captain Jacques Pelet, Count of Beaufranchet, and "seigneur d’Ayat", which gave her 200 000 pounds in dot, 1000 pounds in marital fees, not including the 50 000 pounds which he gave to her husband.