The Apsidal Arch at Santa Maria Maggiore

5th century
Santa Maria Maggiore, Rome

What was designed as an apsidal arch became a "triumphal arch" when the apse was moved back to make space for a transept. Above is the center of the arch, with St. Peter (left) and St. Paul flanking an image of a throne with the cross representing the person of Christ.

Even at this early date, SS. Peter and Paul have the faces artists will use ever after: a square beard for Peter and a pointy beard for Paul, who is balding from the front of his head. Behind them, as if arranged on a low balcony, are symbolic representations of the evangelists (left to right): Luke, Matthew, Mark, and John. The symbols are based on the four winged creatures "round about the throne" in Revelation 4:6-8.

The following photographs of the arch are available:

Read more about crosses and crucifixes.
Read more about images of St. Peter.
Read more about images of St. Paul.

Photographed at the basilica by Richard Stracke, shared under Attribution-NonCommercial-ShareAlike license.