I came across a very stupid theory 'The Divine Right of Kings'. A brief introduction to its basics:

Divine Right basics.

Definition

1. In every kingdom, the king's power comes directly from God, to whom the ruler is accountable; power does not come to the king from the people and he is not accountable to them.

2. In every kingdom, the king makes the final decisions on all aspects of government (including the church). Other people and institutions that exercise political power do so as delegates of the king, and are subordinate to him.

3. However tyrannically kings act, they are never to be actively resisted. (The doctrine of non-resistance).
   If the king orders an act directly against God's commands, the subject should disobey but must submissively accept any penalty of disobedience. (The doctrine of "passive obedience").
   The doctrine was neatly encapsulated in the satirical song, The Vicar of Bray, which insisted that "Kings are by God appointed, /And damned are they that dare resist, / Or touch the Lord's anointed".

4. Monarchy is the best form of government, but other forms are valid.

5. (Some - but far from all - adherents of the Divine Right of Kings also maintained the principle of indefeasible hereditary right: i.e. the belief that while the legitimate heir to the crown is alive it is wrong to swear allegiance to any other ruler, even one actually in possession of power).

Source- http://history.wisc.edu/sommerville/367/367-04.htm

Now, this theory is not as stupid as it looks. The basic contention is good enough- to judge is to be superior. Hence, inferiors cannot judge superiors. Hence, subjects cannot judge kings.

The theory requires a basic theistic framework. If one does not believe in God, the theory is invalid.

Now, as God is the only "superior" for a king, the king is responsible to God only. The only problem is- Why should we accept the king as God's deputy? If we accept the position of God on the caveat that if God did not want the king to rule, than God would have disposed him than there is no reason to develop (cultivate) any feelings of deference, loyalty, and obedience towards kings. If God wants me to have these feelings towards kings, God would develop them. And if I have thoughts to depose the king, there should be no reason to suppress these thoughts. If God didn't want to depose the king, why did God give me such ideas? So this theory has no basis for generating loyalty and support for the king. A straightforward assertion of "might is right" would have been cheaper and less hypocritical.