Person
John IV, Duke of Brittany
Duke of Brittany and Count of Montfort
John IV the Conqueror KG (in Breton Yann IV, in French Jean IV, and traditionally in English sources both John of Montfort and John V) (1339 – November 1, 1399) is Duke of Brittany and Count of Montfort from 1345 until his death and 7th Earl of Richmond from 1372 until his death.