A complete biography of St. Augustine of Canterbury it is impossible to write: almost all that is known of him is his work as a missionary to the English, and almost the only source of our knowledge of that missionary work is the "Ecclesiastical History" of Baeda. But the mission of St. Augustine was one of the great crises, not only of the history of the Christian Church, but of the history of human civilization. The difference between a number of Celtic churches, with bishops largely subordinate to the abbots of monasteries, included (as it seems) in none of the great Catholic patriarchates, cut off from all communication with the great centres of human thought and life--and a Church of England taking her place, at once independent and subordinate, in the swift development of human progress, both conservative and creative--this difference is quite incalculable. And the mission of St. Augustine made the difference. The triumph of Christianity depended--apart from its divine authority--upon the thorough organization of the Christian communities; and that organization had for its centre the Episcopacy. But as separate congregations without a bishop could never have escaped disintegration, so the united congregations, with their presbyters and bishop, would have been powerless without some further organization, uniting the bishops, with well-defined regulations, under some recognized hierarchy of authority. Thus arose metropolitan sees, and the great patriarchates of the Catholic Church--Jerusalem, Antioch, Rome, Alexandria, Constantinople. This centralization was rendered necessary by the course of events; but it had otherwise no divine authority and might be modified just as validly as it was created. When the Roman Empire was submerged under the deluge of barbarian races, a yet closer centralization became necessary, at least in the West; and the ark in which floated over that terrible deluge not only the Christian religion, but the remains of ancient civilization, both Greek and Roman, was the patriarchate of Rome. The man who not only clearly perceived, but was absolutely compelled to assume, his awful responsibility in the West, the Saviour at once of the Church and the world, was the splendid pontiff, Gregory the Great; the great pontiff who sent St. Augustine and his companions to preach the gospel to the English conquerors of Britain. If we would clearly understand the work of St. Augustine we must free our minds from the illusion produced by familiar names. One of these is the name Britain. In the time of Gregory the Great the island called by that name was, of course, the same as that on which Julius Caesar had landed. The barbarians whom Caesar encountered had been subdued by his successors, and a Roman province had been formed. Roman civilization had been introduced and, one might almost say, had flourished. The Christian religion had found its way thither; there had been Christian congregations and bishops, and even a heresiarch.