Keeper of Antiquities: Irish Sacrificed their Kings Horribly if Things Turned Bad in the Kingdom

A kind of early 'checks and balances,' if you will.

"The king had great power but also great responsibility to ensure the prosperity of his people. Through his marriage on his inauguration to the goddess of the land, he was meant to guarantee her benevolence. He had to ensure the land was productive, so if the weather turned bad, or there was plague, cattle disease or losses in war, he was held personally responsible."

There's a famous similar argument made by Þorgnýr the Lawspeaker in the Heimskringla. The pagan mythos has been bleached out, but the 'checks and balances' sentiment remains.

[Our king] wants to have the Norway kingdom laid under him, which no Swedish king before him ever desired, and therewith brings war and distress on many a man. Now it is our will, we bondes, that thou King Olaf make peace with the Norway king, Olaf the Thick, and marry thy daughter Ingegerd to him. Wilt thou, however, reconquer the kingdoms in the east countries which thy relations and forefathers had there, we will all for that purpose follow thee to the war. But if thou wilt not do as we desire, we will now attack thee, and put thee to death; for we will no longer suffer law and peace to be disturbed. So our forefathers went to work when they drowned five kings in a morass at the Mula-thing, and they were filled with the same insupportable pride thou hast shown towards us. Now tell us [king], in all haste, what resolution thou wilt take.