The tastes and sympathies of Aurelius would have led him to choose a life passed in retirement and study at the capital; but hostile movements of the Parthians, and especially invasions of the barbarians along the Rhenish and Danubian frontiers, called him from his books, and forced him to spend most of the latter years of his reign in the camp. The Parthians, who had violated their treaty with Rome, were chastised by the lieutenants of the emperor, and Mesopotamia again fell under Roman authority.
This war drew after it a series of terrible calamities. The returning soldiers brought with them the Asiatic plague, which swept off vast numbers, especially in Italy, where entire cities and districts were depopulated. In the general distress and panic, the superstitious people were led to believe that it was the new sect of Christians that had called down upon the nation the anger of the gods. Aurelius permitted a fearful persecution to be instituted against them, during which the famous Christian fathers and bishops, Justin Martyr and Polycarp, suffered death.
It should be noted that the persecution of the Christians under the Pagan emperors, sprung from political rather than religious motives, and that this is why we find the names of the best emperors, as well as those of the worst, in the list of persecutors. It was believed that the welfare of the state was bound up with the careful performance of the rites of the national worship; and hence, while the Roman rulers were usually very tolerant, allowing all forms of worship among their subjects, still they required that men of every faith should at least recognize the Roman gods, and burn incense before their statues. This the Christians steadily refused to do. Their neglect of the service of the temple, it was believed, angered the gods, and endangered the safety of the state, bringing upon it drought, pestilence, and every disaster. This was the main reason of their persecution by the Pagan emperors.
But pestilence and persecution were both forgotten amidst the imperative calls for immediate help that now came from the North. The barbarians were pushing in the Roman outposts, and pouring impetuously over the frontiers. To the panic of the plague was
