The work consists of a study of Monarchy, a political- philosophy treaty written by Dante Alighieri (1265-1321) in the beginning of the XIV century. The author constructs a model of society based on the duality of powers, with the objective to elaborate a definitive defense of the ideal Empire. The approach takes into account the singular nature of the work in relation to the intellectual production referring to the Empire theory, that circulated during Middle Age´s last centuries. The singularity is not in the form of Dante´s proposal of government - the universal government of just one - but in the argumentation that defines distinct actuation areas between secular power and spiritual power, responsible for guarding humanity to its double end. In the medieval conception of wold, based on the experience of unity between the transcendent and the immanent, the dualism over which Dante constructs his thesis showing a possibility of comprehension of the way favoured by modern thought.