Signet ring of the Black Prince. In 1337, Edward, the Black Prince was created Duke of Cornwall, taking precedence over all earls. Dukedoms were reserved for members of the Royal Family until 1387, when Robert de Vere, 9th Earl of Oxford, the favourite of Richard II, was created Duke of Ireland for life. De Vere had previously been created Marquess of Dublin for life, making him the first person to hold a dignity of such a rank between Dukes and Earls.
Tomb of Edward The Black Prince (1330-1376), Canterbury Cathedral. Remembered as a great war captain, his greatest victory was at Poitiers in 1356, where he captured the French king, Jean II and his rich baggage.
Joan of Kent, first Princess of Wales (1328-1385) was the wife of Edward the Black Prince. Their marriage was a love match; the Plantagenet sons of Edward III had a tendency to defy convention & follow their heart. While Edward & Joan never became King & Queen of England, their surviving son became Richard II. Edward treated his wife affectionately in public & in private; his letter to her seven years after their wedding began, "My dearest and truest sweetheart and beloved companion."