The significant document signed in 1215 that limited the powers of the English monarchy is the Magna Carta, also known as the Great Charter. Signed by King John of England at Runnymede, the Magna Carta established the principle that everyone, including the king, was subject to the law. It laid the groundwork for constitutional governance and protected certain civil liberties, such as the right to a fair trial. The Magna Carta has been regarded as a cornerstone of modern democracy, influencing legal and political thought throughout history and serving as a symbol of the fight against tyranny and for individual rights.