What significant document was signed by King John of England in 1215?

The significant document signed by King John of England in 1215 is the Magna Carta, which means "Great Charter" in Latin. This foundational document was created in response to King John's unpopular rule and the strained relationship between the crown and a group of rebellious barons. The Magna Carta established the principle that everyone, including the king, is subject to the law. It aimed to limit the powers of the monarch and protect the rights of the nobility, but it also laid the groundwork for future democratic developments, including the establishment of due process and the idea of individual rights.

The Magna Carta is often seen as a cornerstone of modern democracy, influencing legal systems and constitutional frameworks in various countries. It set a precedent for the rule of law and inspired later documents, such as the English Bill of Rights and the United States Constitution. Its legacy continues to affect political thought and legal principles around the world.