The divine right of kings is a (largely now considered archaic and defunct) justification of a king or queen's right to rule by virtue of the claim that he or she was given the right to rule by God. In some cases this line of argument was extended to assert a divine ancestry thus further ideologically legitimising the process of rule.

The notion of divine right of kings was certainly in existence anterior to the medieval period, however it was during this time that the notion became extensively used as a primarily political mechanism i.e. for increasing the power of kings within centralized monarchies relative to their subjects.

Saint Augustine in The City of God defines a Christian monarchy in his dualistic concept of Two Cities. The Two Cities are the City of God, the spiritual world, and the City of Man, the secular world. According to Augustine, the City of Man was created by God to protect the City of God and thus monarchs are enthroned by God for a particular purpose, the protection of the City of God. To question their (and by extension, God's) authority is to question God's purpose for both the City of Man and the City of God, and thus not only politically dangerous but spiritually dangerous to the point of heresy.

These arguments are exemplified and taken further still in the following passages from Chapter 20 of James I's Works:

The state of monarchy is the supremest thing upon earth; for kings are not only God's lieutenants upon earth, and sit upon God's throne, but even by God himself are called gods. There be three principal similitudes that illustrate the state of monarchy: one taken out of the word of God; and the two other out of the grounds of policy and philosophy. In the Scriptures kings are called gods, and so their power after a certain relation compared to the divine power. Kings are also compared to fathers of families: for a king is truly Parens patriae, the politique father of his people. And lastly, kings are compared to the head of this microcosm of the body of man.

Kings are justly called gods, for that they exercise a manner or resemblance of divine power upon earth: for if you will consider the attributes to God, you shall see how they agree in the person of a king. God hath power to create or destroy, make or unmake, at his pleasure, to give life or send death, to judge all and to be judged nor accountable to none; to raise low things and to make high things low at his pleasure, and to God are both souls and body due. And the like power have kings: they make and unmake their subjects, they have power of raising and casting down, of life and of death, judges over all their subjects and in all causes and yet accountable to none but God only.

I conclude then this point touching the power of kings with this axiom of divinity, That as to dispute what God may do is blasphemy, so is it sedition in subjects to dispute what a king may do in the height of his power. But just kings will ever be willing to declare what they will do, if they will not incur the curse of God. I will not be content that my power be disputed upon; but I shall ever be willing to make the reason appear of all my doings, and rule my actions according to my laws. [..]

See also: regicide

The Divine Right of Kings is also the title of a short poem by Edgar Allan Poe