It should be mentioned that one other nearly contemporary authority, the Greek historian Zosimus, alludes to the collapse of Roman rule in Britain, which he attributes to a revolt of the natives, following on the departure of the usurper Constantine with the legions. His language, however, is obscure and even self-contradictory, and he throws little light on the situation. The authority which we have next to consider is the _Life of St. Germanus_, written by the presbyter Constantius about the year 480. It will be seen that this document is not strictly contemporary, the writer being separated by an interval of about half a century from the chief events recorded by him: and, moreover, there is throughout the Life a tendency to glorify the saint by attributing to him various manifestations of a miraculous or semi-miraculous kind, which does not increase our confidence in his trustworthiness as a historian. But all students of early medieval history are accustomed to this kind of document, in which every remarkable event in the life of the subject of the biography is invested with a halo of thaumaturgic sanctity, and though they are not the sort of historic materials which we prefer, we must accept them (while making our own private reservations as to the amount of faith which we repose in all their details) or give up writing the story of the Middle Ages altogether. In the case before us, the missionary Germanus, whose adventures in Britain are related by the biographer, was a great and well-known historical personage. He had held, under the empire, the high military dignity of duke of the Armorican shore (Normandy and Brittany), had been consecrated Bishop of Auxerre against his will, had thereupon said farewell to the delights of sportsmanship, and entered earnestly on the duties of his new calling. He had as a fellow-missionary, Lupus, who many years after, as Bishop of Troyes, earned great renown by dissuading the savage warrior, Attila, from an attack on his cathedral city. It is a striking testimony to the character of both men that their contemporary, Apollinaris Sidonius, when he wishes to celebrate the virtues of another eminent prelate, Anianus, Bishop of Orleans, can find no higher term of praise than this: “He was equal to Lupus and not unequal to Germanus”. Such were the two men who in the year 429 were sent at the bidding of Pope Celestine, and in conformity with the resolutions of a synod of Gaulish bishops, “to purge the minds of the people of Britain from the Pelagian heresy and bring them back to the Catholic faith,” that is, to the Augustinian teaching on free-will and the Divine grace. Their zealous preaching won over the multitude to their side, but the Pelagians, who seem to have been found chiefly among the wealthier Britons, challenged them to a public discussion, in which their simple earnestness prevailed over the elaborate rhetoric of the gaily clothed orators on the other side. A miracle followed: the