Another mention of a Mercurio Bua exists in the "Histoire des guerres civiles de France" by Enrico Caterino Davila. There a man named Mercurio Bua was active in the service of the king of France in the 1580s. He was present as a commander of a unit of light cavallery at the Battle of Coutras in 1587, leading an ill-fated cavallery charge that led to his unit being diverted away from the decisive action, thus contributing to a catastrophic defeat of the royal army. Nevertheless, it is unknown if it is the same person.