After a period of deterioration the twelfth and thirteenth centuries witnessed the renewal of regional monarchies, with both beneficial and detrimental consequences for the empire. The imperial office recovered much of its own strength, but the renovation of the monarchies also went against the envisioned universal temporal kingdom or dominium mundi. In the imperialists’ view the emperor had supreme authority, and was the superior to the so called ‘régulos’. One cannot understand the mind-set of the supporters of the imperialist cause unless one takes into consideration the perceived necessity of this single supreme authority, which stemmed from the eschatological view that the unity of Christendom must be maintained in preparation for the
