His bravery, however, was fatal to him.

A Catholic named Maurevel, tempted by the fifty thousand crowns that had been offered for the assassination of Coligny, had entered the Protestant camp, pretending that he had been badly treated by the Guises.

No opportunity for carrying out his design against the Admiral presented itself, and he remained at Niort with De Mouy; who, believing his protestations of attachment for the cause, had treated him with great friendship.

As the Huguenots were returning after their successful sortie, he was riding in the rear with De Mouy and, seizing his opportunity, he drew a pistol and shot the Huguenot leader, mortally wounding him.

He then galloped off and rejoined the Catholics; and was rewarded, for the treacherous murder, by receiving from the king the order of Saint Michael, and a money reward from the city of Paris.
The garrison of Niort, disheartened at the death of their leader, surrendered shortly after.