Huguenots are member of a French Protestant denomination with origins in the 16th or 17th centuries. Historically, Huguenots were French Protestants inspired by the writings of John Calvin (Jean Cauvin in French) in the 1530s, who became known by that originally derisive designation by the end of the 16th century. The majority of Huguenots endorsed the Reformed tradition of Protestantism. Hans J. Hillerbrand in his Encyclopedia of Protestantism: 4-volume Set claims the Huguenot community reached as much as 10% of the French population on the eve of the St. Bartholomew's Day massacre, declining to 7-8% by the end of the 16th century, and further after heavy persecution began once again with the Revocation of the Edict of Nantes by Louis XIV of France.