The document signed in 1215 that limited the powers of the English monarchy is the Magna Carta. This landmark charter was created to address the grievances of rebellious barons against King John of England. It established the principle that everyone, including the king, was subject to the law. The Magna Carta is often regarded as a foundational text for modern democracy and the rule of law, influencing many constitutional documents around the world, including the United States Constitution. Its legacy continues to shape discussions on individual rights and governmental power.