権利の請願
Released to attend Parliament, Hampden was closely involved in its efforts to limit the king's power, the first being adoption of the Petition of Right in June 1628. This opened the way to a new impeachment of Buckingham, which ended when he was assassinated in August by a disgruntled soldier. The next issue was that of Roger Maynwaring and Robert Sibthorpe, two priests who published sermons supportive of supporting the divine right of kings, passive obedience, and implying Charles did not need Parliament's approval to raise taxes.