Each of these important documents in English constitutional history had a similar purpose--to assert the fundamental liberties of English subjects, to protest that the King was violating these liberties, and to exact a promise from the monarch that he would respect English liberties in the future. The Petition of Right, issued to Charles I from Parliament in 1628, repeatedly refers to Magna Carta among other statutes and charters as the source of such liberties as trial by jury and habeas corpus. Many of the demands in the petition are the same as in Magna Carta, including parliamentary approval for taxation. One major difference is that by the time the Petition of Right was issued, Parliament was conceived, in theory at least, as a body that represented all of the English subjects. It also had become established as a permanent feature of the English constitution. Parliament, in short, was nonexistent in 1215, when Magna Carta was promulgated--in fact it was Magna Carta's stipulation that the King could not tax barons without their consent planted the seeds for what would become Parliament. Magna Carta made no pretense of being representative of all of the English people, a concept that simply did not exist in the thirteenth century. What it was, really, was a codification of the feudal relationship between the King (in 1215, this was John) and his nobles, or barons. Nothing about Magna Carta guaranteed basic rights to English subjects, though it would serve as the foundation for documents, such as the Petition of Right itself, that would do exactly that.