Il rapporto tra regnum e sacerdotium nell’ecclesiologia di Leone IX

Abstract

The relationship between regnum and sacerdotium plays a central role in the ecclesiological reflections of Leo IX. In his doctrinal letter In terra pacis (1053) – for the first time in a papal document – he quoted extensively from the Constitutum Constantini in order to illustrate the legitimacy of the temporal dominion of the Roman Church. However, this power is not ultimately traced back to the Donation of Constantine, which, according to Leo IX, simply gave back to the Roman Pontiff what God himself had conferred upon him by virtue of the exclusive “royal priesthood” (1 Peter 2:9) of the Apostolic See. This conception, still far from properly hierocratic developments, is part of a harmonious vision of the relationship between papal and imperial power, which Leo IX effectively outlined in his letter to the basileus Constantine Monomachos (1054). The two emperors, described in a unitary perspective as the two "arms" of the Church, are exhorted to protect the ecclesial primacy and the property rights of the Apostolic See, as well as to defend it from any external threat.