Communication in a visual mode: papal apse mosaics

ABSTRACT

Apse mosaics are a form of visual communication employed by popes throughout the Middle Ages, from the sixth through to the thirteenth centuries. This essay examines the nature of this visual mode and the means by which viewers could understand it. A theory of viewing widely attributed to Pope Gregory I (590–604) is shown to be especially pertinent to early medieval apse mosaics and to the twelfth-century mosaic in the apse of S. Maria in Trastevere. The apses of thirteenth-century popes display a new, more explicit approach to visual messaging that required less interpretive effort by the viewer. Two mosaics made at the end of this century were signed by the artist who made them. The emergence of the artist as a competing author of the image diminished the utility of this form of papal visual communication, which immediately fell out of use.