Charles, Duke of Brittany was a 14th-century nobleman who ruled the duchy from 1341 until his death in 1364. Born in Blois, he claimed the territory through his marriage to Joan, the Duchess of Brittany. A deeply religious man known for his extreme asceticism, he participated in the Breton War of Succession against the House of Montfort. He died during the Battle of Auray, a conflict that eventually concluded the succession struggle.