The “Double Apostolate” as an Image of the Church. A Study of Early Medieval Apse Mosaic in Rome

As large cities claimed apostolic founding of their churches, the Roman church declared that it was constituted on the “double apostolate” of Peter and Paul. The concordia apostolorum which results from the final agreement between the “former rivals” in this city is also seen as the foundation of the Roman church. The term concordia apostolorum has been applied to at least two image types which show the two apostles together. I propose that this name is more appropriate as a title for the well known Roman apse image of Christ flanked by the apostle princes than the traditional traditio legis, since the concordia and the double apostolate are concepts which relate the church to the city of Rome. Hence, the scheme with the two apostles which decorates so many Roman apses from Late Antiquity until the age of Paschal I can be seen as an emblem precisely of the Roman church.