Ah, the glories of Medieval political thought! I love this one!
Therefore even as the royal dignity and authority excels all earthly authorities, so no infamous or shameful man is appointed to administer it, but he who no less in wisdom, justice, and piety than in place and dignity is superior to others. Therefore it is necessary that he who is to bear the charge of all and govern all should shine above others in greater grace of virtues and should strive to administer with the utmost balance of equity the authority allotted to him. For the people do not exalt him above themselves in order to grant him a free opportunity to exercise tyranny against them, but that he may defend them from the tyranny and unrighteousness of others. Yet when he who has been chosen for the coercion of the wicked and the defence of the upright has begun to foster evil against them, to destroy the good, and himself to exercise most cruelly against his subjects the tyranny which he ought to repel, is it not clear that he deservedly falls from the dignity entrusted to him and that the people stand free of his lordship and subjection, when he has been evidently the first to break the compact for whose sake he was appointed? Nor can anyone justly and rationally accuse them of faithlessness, since it is quite evident that he first broke faith. For, to draw an example from baser things, if someone should entrust his pigs to be pasture to someone for a fitting wage, and afterwards learned that the latter was not pasturing them, but was stealing, slaughtering, and losing them, would he not remove him with reproaches from the care of the pigs, retaining also the promised wage? If, I say, this principle is maintained in regard to base things, that he is not considered indeed a swineherd who seeks not to pasture the pigs, but to scatter them, so much the more fittingly, by just and probable reason, in proportion as the condition of men is distinct from the nature of pigs, is he who attempts not to rule men, but to drive them into confusion, deprived of all the authority and dignity which he has received over men….It is one thing to reign, another to exercise tyranny in the kingdom. For as faith and reverence ought to be given to emperors and kings for safeguarding the administration of a kingdom, so certainly, for good reason, if they break into the exercise of tyranny, without any breach of faith or loss of piety no fidelity or reverence ought to be paid them.
- Manegold of Lautenbach, Ad Gebehardum Liber, ca. 1085 A.D., as cited by Ewart Lewis, Medieval Political Ideas, Vol. 1 (New York: Cooper Square Publishers, Inc., 1974), pg. 165