 Because Huguenots were persecuted at this time in France, and their career prospects were limited, it is thought that du Casse forged his baptismal record to hide his Huguenot and ignoble background.Early biographers, including his grand-nephew and Saint-Simon, perpetuated this error in their works.Du Casse admitted his family's religious background in a letter to Naval Minister Pontchartrain in 1691, and local records from Pau also support the Huguenot origins of the du Casse family.