Michel Le Nobletz was a 17th-century Catholic missionary and theologian who worked extensively in western Brittany. Born in 1577 to a noble family in Plouguerneau, he pursued rigorous studies in theology and ancient languages before dedicating himself to a life of poverty and evangelization. He is best known for his innovative teaching methods, such as using musical compositions and distinctive painted placards to communicate religious messages to sailors and farmers. Although his intense moral rigor earned him the nickname "the mad priest," his efforts contributed to a significant religious revival in the region.