lywelyn the Great was the supreme leader of the Welsh Lords during the end of King John's reign and early years of Henry III's reign. Llywelyn signed a peace treaty with King John in 1200 or 1201 ensuring good relations between England and Wales for several years and a marriage was arranged between the Welsh prince and King John's daughter Joan. Joan was not the daughter of either of the Isabellas that John married, At the end of King John's reign, Llywelyn fought against the English when they tried to conquer Wales and sided with the barons who forced King John to sign the Magna Carta in 1216.In 1218 Llywelyn signed a peace treaty at Worcester confirming the Welsh leader's ownership of lands including those he had recently captured.














