 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.