The Declaration of Arbroath was affirmed at Arbroath Abbey on the 6th of April 1320. The Declaration decreed that should the king be deemed to be an ineffectual leader then his subjects had the right to replace him - this was back in the days when being a complete  f*ck head was seen as being undesirable in a leader, unlike now where it is a necessary attribute to become leader of the 'free world'