CONTEXT
In 313 AD, Emperor Constantine established the toleration of Christianity in the Roman Empire with the Edict of Milan. No longer rooted in domestic churches, the faith could now express itself in its architecture. Christianity would create its own architectural style of high order, vast layout, resplendent materials, and communal character.
The hierarchy of the Church and the representation of her imperial patron demanded a new framework that separated itself from pagan worship. The model for the large scale churches had to correspond with the highest class of public buildings. The basilica, used as a public court in civic and imperial forms, met this objective and was adopted as the model for the Church. The apse of the basilica would become the canvas for some of the most extravagent mosaics in art history.