King John ruled England for almost two decades (1199-1216) and was well known as a heavy handed ruler. He would often wage unnecessary wars and burden his subjects with heavy taxes to pay for them. King John begrudgingly signed the Magna Carta because he needed the barons to fight his wars and collect his taxes.
It declared that Texas was a free and independent state, subject only to the Constitution of the United States, that all free men have equal rights, and that the writ of habeas corpus could not be suspended or unduly delayed. It has our bill of rights.