The Byzantine Era
Two hundred years after Petra bowed to Roman rule, radical changes swept the empire. In AD 330 Rome's first Christian emperor, Constantine I, shifted his capital eastward a thousand miles, to the city of Byzantium. Renamed Constantinople, this metropolis would now be the seat of Roman emperors. In the new Byzantine Empire, churches--not roads, theaters, or triumphal arches--would signal imperial presence in the provinces.
Though Petra at first clung to its old, officially pagan, gods, Christianity slowly took root. By AD 350 the city boasted its own bishop; a century later it had large Christian churches. But increasingly bypassed by shifting trade routes, Petra had lost its real source of power--commerce. The city, still reeling from the earthquake of AD 363, began its slow decline. The Muslims who swept through the region from southern Arabia in the early 600s seem to have skirted Petra. Yet by AD 700, the valley and ridges once home to perhaps 20,000 people held only a tiny remnant population. Sheep and goats grazed peacefully in Petra's once noisy squares.