whose image
In the last post about Picture Interpretation, we talked about the fact that the background story that the iconography alludes to is a significant part in making the picture understandable, bringing into relief features that may be opaque (or even irrelevant otherwise).
At the same time, the background story can change over time, too. Motifs and images that were originally developed (esp. if they are stylized subject matters) can migrate to different backgrounds, where the take on a new meaning. The ability to migrate and become resident in a new background is the flip side of the ambiguity of the iconography; one cannot have one without the other. In fact, if the images were not movable in that fashion, they would basically be individual denoting like a serial number or a definite description (that individual could of course itself denote a type, as in the case of prototypes or exemplars).
This in a nut-shell is the problem of determining where early Christian art starts. Christian art was a late-comer in several ways. It started out in the lower segments of the populace, those without the funds to acquire objects decorated just for them, or even to commission new decorations. It was a late-comer in terms of religious decoration; the Jewish religion, from whose font early Christianity had drunk deeply, had worked out its own illustrative program. And then of course, Christianity found itself embedded into the larger koine of the classical art of antiquity, with its mosaics, statues, seal rings, funary infrastructure, decorated public spaces and book illustrations (mainly the epics).
One has to remember that art in Antiquity was a building block system, where artists offered catalogs of motifs, and icons drawn from these catalogs could be combined as much as the purse and the tastes of the customer required. Since Christianity only made slow progress, esp. in Rome, from the lower to the middle classes that could actually acquire custom-made art, the early Christian art works are composites based on the standard building blocks. Among these building blocks were such later classics as depictions of fish, of boats and fishermen, and of bucolic scenes such as the young beardless man carrying a sheep on his shoulder (a reference to the Elysian fields, the Graeco-Roman conception of Paradise).
Thus, for the first two hundred years after the beginning of the common era, there are no works of art that can be unambiguously classified as Christian art: some of the bucolic depictions or shipping scenes might be, but we have no way of convincingly proving it. In the case of the iconography referencing stories from the Hebrew Bible, the situation is even worse: The oldest depiction of the standard iconography for the ark of Noah, a box with a man, a dove and a tree branch, comes from a Jewish coin from the area around Mount Arat (where the ark is supposed to have landed). Even for the third century, it is often the case that the only way to be sure that it is in fact Christian art is if there is a plethora of motifs together that are not usually found in that concentration. Thus, a depiction of Noah's ark, together with the Good Shepard, and maybe Adam and Eve and the Tree of Knowledge, is a good candidate for a Christian depiction; two fish is not.
The ambiguity of the imagery was exploited explicitly during the persecutions of the Christian religion. The fact that most of the iconographic depictions could have other meanings too must have been very helpful in that context (provided one was willing to become a lapsus, a fallen one.
With the ascent of the Emperor Constantine I (and his mother Helena), Christianity becomes an imperially supported religion. The battling of heresies now becomes a question of imperial cohesion, and the earlier argument of the claim to apostolic succession acquires new poignancy. The new imperial program requires both that new imagery is developed-depictions of the life and miracles of Jesus-and that old imagery that was earlier associated with the cult of the Emperor now comes into reach: On one of the mid-fourth century Roman coffins, the Risen Christ thrones on an unabashedly imperial throne, while the crucification scene is decorated with a laurel garland held by an eagle (the bird of Jupiter, the State god par excellance). The adoration of the Magi depicts the Virgin Mary seated on a throne not unlike the one that the emperor mother occupied.
However, Constantine and his mom, nouveau riche upstarts from the Germanic provinces around Trier and Cologne, never settle down socially in Rome, and eventually, after falling out with the Roman Senate, decide that Rome had its day and move the operation to Constantinople. The emphasis on Peter and Paul as the legendary founders of the Roman Christian community now become claims to importance in a Christianity that has shifted its emphasis to the large and early congregations of the East: Antioch, Alexandria, and of course the newly funded Constantinople with its own Patriarchy.
Whether it is the support of Constantine or the need for Rome to re-emphasize its importance in this moment of apparent decline, the hand-off to the new Moses, Peter, now needs to be worked out in inventive iconographic detail. The traditio legis, the transfer of the new Law, and the traditio clavis, the handing-over of the keys of the Kingdom of the Heavens, to Peter become new images to illustrate lamps, seals, belts, sarcophagi and table ware, both in Rome and in the Gallic provinces that import from the Eternal City. The transfer of the semantics brings with it a transfer in the iconographic backdrop; a legend develops of Peter striking water from the wall of his cell in Rome, as Moses struck water from the rock at Mount Horeb, but not to satiate physical thirst but to baptize his prison guards that he has converted: a spiritual thirst. The iconography for Mount Horeb and for the prison baptismal font remains the same, making it difficult to decide for some of the earlier works whether Moses or Peter is being depicted.
Under the imperial demand for a unified Christianity, the old partnership of Peter and Paul, first worked out in Acts as a harmonization of missionary interests, receives renewed attention. Paul accompanies Peter in the moment of accepting the new law or the keys of the Kingdom of the Heavens, as a witness and as an acclamator. A lamp of the time depicts the ship of the Church, with Peter and Paul driving in it. Constantine I builds two basilikas in Rome, St Peter and San Paolo fuori le muro. Their mutual support, rendered in depictions of embracement and similar, brings with it an iconographic problem: How to tell Peter from Paul? It is apparently at this time that Paul acquires his classical bald globe that has been his iconographic feature, even down to modern children's bibles. The other apostles require no distinction yet (though Paul is used to completement their number to twelf, replacing Matthias who had replaced Judas Iscariot); their martyr-tool-based denotation system is an invention of later ages faced with a similar problem.
By the close of the fifth and the beginning of the sixth century, with the Roman Empire in serious decline, Christian art has completed the fusion of the Biblical background and the artistic capabilities of Antiquity. Monestaries in the East stored their capital by creating biblical manuscripts on purple-dyed vellum with gold lettering. The thoroughly Christian emperors commission their Christian art at the imperial workshops, producing exquisite works of representational, devotional and propagandistic art. The question of how the Emperor can fit into the apostle team, which Constantine solved in his funary chapel by arraying the apostles in a circle around his sarcophagus, is now resolved by bringing the hero of the Jewish Bible, David, into the iconographic program. The Emperor is the new David, the Champion of the Lord. When his martial virtues are not the point of emphasis, he is depicted in prayer, the first of the servants of God.