The fundamental political principle established by the Magna Carta in 1215 is the principle of the rule of law, which asserts that everyone, including the king, is subject to the law. This landmark document arose due to conflicts between King John of England and his barons, who sought to limit royal power and protect their rights. The Magna Carta laid the groundwork for the development of constitutional law, emphasizing that no one is above the law and that individuals have certain inalienable rights. Over time, it has become a symbol of democracy and justice, influencing legal systems around the world.