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.
Edward of Woodstock, Prince of Wales, Duke of Cornwall, Prince of Aquitaine, KG (15 June 1330 – 8 June 1376) was the eldest son of King Edward III of England and his wife Philippa of Hainault as well as father to King Richard II of England.
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.