Taxation
Under Magna Carta the King cannot impose taxes without the approval of the "common counsel" of the kingdom (1215)
Found in: Magna Carta: A Commentary
No scutage nor aid shall be imposed on our kingdom, unless by common counsel of our kingdom, except for ransoming our person, for making our eldest son a knight, and for once marrying our eldest daughter; and for these there shall not be levied more than a reasonable aid. In like manner it shall be done concerning aids from the city of London.