ใครแต่งงานกับJohn IV, Duke of Brittany?

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 – 1 November 1399), was Duke of Brittany and Count of Montfort from 1345 until his death and 7th Earl of Richmond from 1372 until his death.

Lady Joan Holland (1350 – October 1384) was Duchess of Brittany as the second wife of John IV, Duke of Brittany. She was the daughter of Joan of Kent and Thomas Holland, 1st Earl of Kent. Her mother's second husband was Edward the Black Prince, and the child of that marriage was King Richard II of England.

Joan Holland's marriage to John IV took place in London in May 1366, but without the approval of King Edward III of England, Joan's step-grandfather, who claimed overlordship of Brittany. The couple had no children.

Joan's death, in her thirties, was politically inexpedient. In 1386, two years afterwards, John IV married Joan of Navarre, later the queen of King Henry IV of England.

Mary of Waltham (10 October 1344 – September 1361), Duchess of Brittany, was a daughter of King Edward III of England and Philippa of Hainault and was the wife of John IV, Duke of Brittany, known in England as "John V" and "The Conqueror". Mary was made a Lady of the Garter in 1378.

โยอานาแห่งนาวาร์ (บาสก์: Joana Nafarroakoa; สเปน: Juana de Navarra; ฝรั่งเศส: Jeanne de Navarre; ราว ค.ศ. 1370 – 10 มิถุนายน ค.ศ. 1437) เป็นพระมเหสีของพระเจ้าเฮนรีที่ 4 แห่งอังกฤษและเป็นพระราชธิดาของพระเจ้าการ์โลสที่ 2 แห่งนาวาร์