The pergula of Pope Gregory III (731–741) in the Basilica of Saint Peter

Gregory III is the first pope whose artistic patronage is outlined by the Liber pon­tificalis. This section appears immediately after his response to the new Byzantine policy relating to sacred images. Elected in February 731, Gregory convened in November of the same year a synod in front of the confessio of Saint Peter’s Basil­ica to discuss the ongoing image controversy. Either before or more likely after the synod, he refurbished this area of the basilica with a set of magnificently carved columns. These had been donated by Exarch Eutychius of Ravenna (ca. 727 – 751) and matched in style the set of columns donated by Constantine I in ca. 320 to monumentalise the burial site of Peter. Whilst acknowledging the solid groundwork performed by previous studies in the archaeology and art history of Saint Peter’s confessio, this article deepens the analysis of the ideological implications of Gregory III’s pergula by placing it against the backdrop of the complex political landscape of Italy in the 720s–740s. This period was dominated by major actors: the papacy in Rome, the Byzantine emperor represented by the exarch of Ravenna, and the Lombard king in Pavia. In fact, the image controversy was but one of the political issues at stake. Com­bining the discrete expertise and research methodologies of an art historian and a historian working on religious–political texts and identities, we intend to offer a cultural–historical evaluation of Gregory III’s work on the confessio in light of the wider questions of early medieval papal politics and artistic patronage. We point out that Gregory III’s pergula should not be seen exclusively as a reaction to Byzantine iconoclasm. In fact, by incorporating a precious gift from the exarch of Ravenna, and putting his own stamp on it, Gregory III was situat­ing himself in a lineage of popes who had used artistic patronage to assert their role as bishop of Rome and head of the Christian oecumene. We also note the importance of the relief icons Gregory III placed on the beam running on Eutychius’ columns, agreeing with earlier studies maintaining that they must have been intended and perceived as a strong statement of icono­philia. We add the consideration that, by promoting relief icons in Saint Peter’s, Gregory III affirmed his prerogative as vicar of Peter to establish what was ‘ortho­dox’. The relief icons, aptly combined with the six extraordinary marble columns that were donated by Eutychius and matched the Constantinian set, must have represented what the ideal empire should be: unified and orthodox. Gregory III’s new pergula was indeed a dramatic addition to the area of the confessio. More than anything written in ink and sent to Byzantium through en­voys on perilous journeys, it emerged as a nod to the opportunistic alliance that Rome and Ravenna had cemented in the face of Constantinople and of renewed Lombard military threats. This new alliance was consequential. Not only did it prevent the election of an alternative emperor in Italy and the Lombard con­quest of the Byzantine section of central Italy, de facto it delayed the final detach­ment of Italy from Byzantium until later in the eighth century.