The ancient city of Rome is a layered one. Anyone who has ever had the chance of walking down the streets of this city can see that there is no single defining era of this city. Certainly, there are its classical elements, but the city is as much defined by the great monuments of its Christian era as it is by its earlier incarnations. And some structures, like the church of San Clemente, allow us to see nearly all of its history in a single place, for while the church is most known for the splendor its mosaics and its apsidal arch, its bedrock extends back to the era of the emperors.
Studying this building allows us to understand how the historical and architectural layers of Rome are linked to each other. The 11th and 12th century architectural and decorative elements of this church are clearly distinct from those elements that came before - even as they also help us to see and to understand the changes that came afterwards. The medieval work on San Clemente is linked to the specific historical moment in which it was created and therefore allow us to understand the ways in which the politics, culture, and economy of an era produce one type of art and not another. But perhaps even more importantly, the 11th- and 12th-century work that was done in San Clemente allows us to understand how art and architecture are created that both reflect a particular moment in history in the kind of city that is intensely aware of its place in history. The mosaics and arch were meant both to define this section of the church as belonging forever to the early centuries of the second Christian millennium even as they were also meant to appear to be timeless, part of the before and after of the church as much as of its then-present (Brown, 1978, p. 119).
The triumphal arch and its associated mosaics belong the top layer of San Clemente, both the historically most recent level as well as its most visually prominent aspect. However, while this upper pa...