By emigrating from Chalon to Lérins, and from there to Arles, Caesarius had transported himself from the periphery of the Roman world to its Mediterranean heartland. A Roman possession for nearly 600 years, until the Visigoths took control of it in 476/77, Provence was the most romanized region in Gaul, in the words of Pliny the Elder, writing in the first century AD, “Italy rather than a province.” It was the familiar, Mediterranean character of the place that struck ancient observers most forcefully. Strabo noted that the rivers of Provence, especially the Rhône, drained into the Mediterranean Sea “which is better than the outer sea.” He also observed that the region yielded the same produce as Italy, and that olives, grapes, and figs ceased to grow well at its outer limits. Indeed, in climate, geography, and culture, Roman Provence more closely resembled northern Italy than the rest of Gaul, where people wore trousers instead of tunics, drank beer instead of wine, and in the later empire still measured distances in Celtic leagues rather than Roman miles.

It was in this most Mediterranean and Roman of settings, and specifically in the city and countryside of Arles, that Caesarius would attempt to enact the Christian principles that he had acquired as a monk at Lérins. But Arles had little in common with the tranquil island monastery. Itwas a bustling, noisy, crowded, shabby river port; its territory stretchedfrom the river delta in the south (the Camargue) to the mountains of the north (the Alpilles) and the stony plains of the east (the Crau).