The famous document signed in 1215, which limited the power of the English monarch, is the Magna Carta. Signed by King John of England, this charter established the principle that everyone, including the king, was subject to the law. It included guarantees of certain legal rights, such as due process and the right to a fair trial. The Magna Carta is often considered a cornerstone of modern democracy and legal systems, influencing constitutional law around the world. Its legacy continues to resonate today, symbolizing the fight for liberty and the importance of the rule of law.