Jeanne de Clisson (1300–1359), also known as Jeanne de Belleville and the Lioness of Brittany, was a French–Breton noblewoman who became a privateer to avenge her husband after he was executed for treason by King Philip VI of France. She crossed the English Channel, targeted French ships, and regularly slaughtered almost their entire crew. It was her practice to leave at least one sailor alive to carry her message of vengeance.