After the fall of the [[Western Roman Empire]], most institutions of Roman [[public]] [[law]] fell into disuse, but much of Roman political theory remained. During the early [[Middle Ages]] the Christian world was ruled in theory by the Pope and the [[Holy Roman Emperor]]. The former had the spiritual power, which was identified with [[auctoritas]], while the latter had temporal power, identified with '''potestas'''. At first, the Pope crowned the Emperor and the Emperor appointed the Pope, so they were in a situation of balance, but after the [[Investiture Controversy]] the Pope was instead chosen by the College of Cardinals. | After the fall of the [[Western Roman Empire]], most institutions of Roman [[public]] [[law]] fell into disuse, but much of Roman political theory remained. During the early [[Middle Ages]] the Christian world was ruled in theory by the Pope and the [[Holy Roman Emperor]]. The former had the spiritual power, which was identified with [[auctoritas]], while the latter had temporal power, identified with '''potestas'''. At first, the Pope crowned the Emperor and the Emperor appointed the Pope, so they were in a situation of balance, but after the [[Investiture Controversy]] the Pope was instead chosen by the College of Cardinals. |