John, King of England, ruled from 1199 to 1216. He was the youngest son of Henry II and Eleanor of Aquitaine. His reign is often remembered for conflicts with the nobility and the loss of territories in France, which weakened his power. In 1215, John faced rebellion from his barons, leading to the signing of the Magna Carta. This document limited the king's authority and established certain legal rights, laying the groundwork for modern democracy. John's inability to uphold the agreement contributed to his unpopularity and the eventual civil war during his reign.