I ran across an interesting passage in Sir Henry Vane’s “A Healing Question”. (1656)

He is dealing with the question of how much power kings had  over their people.

One faction, usually the kings themselves, held that kings were appointed and raised up by God, and therefore had ultimate power to do whatever they wanted- called the divine right of kings.

Another faction held that kings only ruled by the consent of the governed.

Vane argues against the first with an appeal to Christian doctrine by claiming “the nations of the world have right and title by the purchase of Christ’s blood, who, by virtue of his death and resurrection, is become the sole Lord and Ruler in and over the conscience; for to this end Christ died, rose, and revived, that he might be Lord both of the dead and of the living, and that every one  might give an account of himself, in all matters of God’s worship unto God and Christ alone, as their own Master, unto who they stand or fall in judgment, and are not in these things to be oppressed, or brought before the judgment-seats of men.” 

He is specifically dealing here with freedom of religion and worship, but there is also a grounding of the larger question of the scope of a king’s rule. Given that Christ is the ruler of all and has purchased men to be his, no human king has ultimate rights over God’s people. He is there to serve as a protector of the rights of the people under his dominion as children of God, and since he too is under that same God, his rights and rule are limited as well. 

I’m sure this grounding was already well known by this time. Since the Magna Carta in 1215AD, there have been legal limits on what the king could do. Vane referenced a popular belief at the time that there was a pre-existing constitution of rights that was overthrown by the Norman invasion in 1066. The main point being the long-standing recognition of fundamental  rights of the governed. We don’t have any copies of the proposed Anglo-Saxon constitution of rights that would have preceded the Norman Invasion, but it’s possible it existed.