King John of England, who reigned from 1199 to 1216, is often remembered for his conflicts with the nobility and his failure to secure territory in France. He was the youngest son of King Henry II and Eleanor of Aquitaine. His reign was marked by disputes with powerful barons, leading to a loss of support and authority. In 1215, King John faced rebellion from his nobles, resulting in the signing of the Magna Carta, a document that limited the king's power and established certain legal rights. This agreement is considered a foundational moment in the development of constitutional law in England.