What is the birthdate of this King of England, son of Edward, the Black Prince, whose court companion was Robert de Vere, Duke of Ireland?
Robert de Vere, Duke of Ireland Robert de Vere, Duke of Ireland, Marquess of Dublin, and 9th Earl of Oxford KG (16 January 1362 – 22 November 1392) was a favourite and court companion of King Richard II of England. He was the ninth Earl of Oxford and the first and only Duke of Ireland and Marquess of Dublin.
Edward of Westminster, Prince of Wales Edward of Westminster (13 October 1453 – 4 May 1471), also known as Edward of Lancaster, was the only son of King Henry VI of England and Margaret of Anjou. He was killed at the Battle of Tewkesbury, making him the only heir apparent to the English throne to die in battle.