King John was the King of England from 1199 to 1216. He is often remembered for his conflicts with the nobility and his failure to secure territories in France. His reign was marked by disputes with powerful barons, leading to a significant loss of support among the aristocracy. In 1215, King John faced rebellion from his barons, resulting in the signing of the Magna Carta. This document limited the king's power and established certain legal rights, laying the groundwork for modern democracy. John's inability to uphold the terms of the Magna Carta led to further conflicts and his eventual downfall.