The origin of the theory of law goes back to the Middle Ages, during the era of Reformation.
The essential role of the theory of law has been to establish the legitimacy of power, the central problem around which the theory of law is organized is the problem of sovereignty,  where sovereignty is the authority that has the power to make law within the state.
Jean Bodin (1576) in France made the first systemic discussion of the theory of sovereignty. Bodin's “theory of sovereignty was the theory upon which the French absolute monarchy was to rest.” 
According to Bodin “law is a command that operates on two levels" The first level is the divine in which law is the command of God, "to which we are all subjects including the absolutist monarch.” 
The second level is the level of the state where law is the command of the absolutist monarch. Bodin's theory was secularized by Hobbes Leviathan (1651), and later on adopted by Bentham and Austin utilitarian tradition in what is known as the command theory of law .
 C.E. Jr. Merriam. History of the Theory of Sovereignty (Kitchener, Ontario: Batoche Books, 2001: 4).
 Christian Reus-Smit. The Moral Purpose of the State: Culture, Social Identity, and Institutional Rationality in International Relations . Princeton, NJ: Princeton University Press, 1999: 97).