Yann v becomes duke of brittany, providing 43 years of economic prosperity and artistic creativity

John V, sometimes numbered as VI, (24 December 1389 – 29 August 1442) bynamed John the Wise (Breton: Yann ar Fur ; French: Jean le Sage), was Duke of Brittany and Count of Montfort from 1399 to his death. His rule coincided with the height of the Hundred Years’ War between England and France. John’s reversals in that conflict, as well as in other internal struggles in France, served to strengthen his duchy and to maintain its independence.