Son of the public prosecutor of the parlement of Bourgogne, Languet de Gercy was a protégé of Jacques Bénigne Bossuet, who introduced him to Louis XIV and had him named as the chaplain to the princess. At the same time he was the general vicar of the diocese of Autun, which includes the parish of Paray-le-Monial where the saint Marguerite Marie Alacoque is buried.
Languet de Gercy, the son of the public prosecutor in Bourgogne's parlement, was a protégé of Jacques Bénigne Bossuet. Bossuet facilitated his introduction to Louis XIV and appointed him chaplain for the princess. Concurrently, he held the position of general vicar for the diocese of Autun, which encompasses the parish of Paray-le-Monial where Saint Marguerite Marie Alacoque is buried.