Gelasius I

Pope Gelasius I (d. 496) was the Bishop of Rome from 492 to 496, a short but historically significant pontificate during which he articulated one of the most influential political theories of the medieval world — the doctrine of the 'two swords,' distinguishing the separate spheres of authority belonging to popes and emperors. Gelasius was likely of North African (Berber) origin, making him one of three popes of African descent. His pontificate was consumed by the Acacian Schism, a rupture between the churches of Rome and Constantinople that had begun in 484 when Patriarch Acacius endorsed a compromise formula on the nature of Christ that the papacy rejected as heterodox. Gelasius's most famous contribution to political thought came in his letter to Emperor Anastasius I (494), in which he distinguished between the 'sacred authority' (auctoritas sacrata) of bishops and the 'royal power' (regalis potestas) of kings — both deriving from God but operating in different spheres. This articulation of the relationship between spiritual and temporal power became the foundation of medieval Western political theory and the basis for the Church's assertion of independence from state control.