After he had served the duchy of Milan and Pope Julius II in various capacities, the outbreak of the plague caused him to move back to France.
There, he made his reputation as a criminal lawyer by his eloquent defense of a group of rats who were put on trial for destroying the barley crop of the province.
During the unrest brought about by the Protestant Reformation in France, de Chasseneuz, though a Roman Catholic, sought to protect the Waldensians.
[4] De Chasseneuz's principal work is the Commentaria in consuetudines ducatus Burgundiae (1517), the first substantial and scientific commentary on the droit coutumier or French customary law.
De Chasseneuz's other works include Catalogus gloriae mundi (1529), an encyclopedic panorama of the author's knowledge, and the Repertorium consiliorum (1531), a collection of legal advice given by him.