The principle established by the Magna Carta in limiting royal power was fundamental in shaping future democratic structures by introducing the concept of the rule of law. Signed in 1215, it asserted that even the monarch was not above the law, laying the groundwork for later developments in constitutional governance. This principle influenced various political documents, including the U.S. Constitution and the Bill of Rights, reinforcing the idea that governmental authority must be balanced with individual freedoms and rights. It served as a crucial step in advancing liberty and justice within society.