The Magna Carta, signed in 1215, is significant to modern political systems as it established the principle of the rule of law and limited the powers of the monarch. It introduced the idea that no one, including the ruler, is above the law, laying the groundwork for constitutional governance and individual rights. This historical document influenced various democratic movements and documents, such as the United States Constitution and the Universal Declaration of Human Rights. Its legacy continues to shape contemporary discussions about justice, liberty, and accountability in governance.