Alix, duchess of Brittany Hereditary Duchess of Brittany 1203-1221, Breton noble (1200–1221) Parents Constance, duchess of Brittany Guy of Thouars Children John I, Duke of Brittany Yolande of Brittany Siblings Eleanor, Fair Maid of Brittany Arthur I Matilda of Brittany Margaret of Thouars Catherine of Thouars Pierre I de Chemillé, Sire de Chemille et de Mortagne Partners Peter I, Duke of Brittany
