Bede's Ecclesiastical History of England, ed. by A.M. Sellar, [1907], at sacred-texts.com

CHAP. XIV. How the Britons, compelled by the great famine, drove the barbarians out of the their territories, and soon after there ensued, along with abundance of corn, decay of morals, pestilence, and the downfall of the nation.

IN the meantime, the aforesaid famine distressing the Britons more and more, and leaving to posterity a lasting memory of its mischievous effects, obliged many of them to submit themselves to the depredators; though others still held out, putting their trust in God, when human help failed. These continually made raids from the mountains, caves, and woods, and, at length, began to inflict severe losses on their enemies, who had been for so many years plundering the country. The bold Irish robbers thereupon returned home, intending’ to come again before long. The Picts then settled down in the farthest part of the island and afterwards remained there; but they did not fail to plunder and harass the Britons from time to time.

Now, when the ravages of the enemy at length abated, the island began to abound with such plenty of grain as had never been known in any age before; along with plenty, evil living increased, and this was immediately attended by the taint of all manner of crime; in particular, cruelty, hatred of truth, and love of falsehood; insomuch, that if any one among them happened to be milder than the rest, and more inclined to truth, all the rest abhorred and persecuted him unrestrainedly, as if he had been the enemy of Britain. Nor were the laity only guilty of these things, but even our Lord’s own flock, with its shepherds, casting off the easy yoke of Christ, gave themselves up to drunkenness, enmity, quarrels, strife, envy, and other such sins. In the meantime, on a sudden, a grievous plague fell upon that corrupt generation, which soon destroyed such numbers of them, that the living scarcely availed to bury the dead: yet, those that survived, could not be recalled from the spiritual death, which they had incurred’ through their sins, either by the death of their friends, or the fear of death. Whereupon, not long after, a more severe vengeance for their fearful crimes fell upon the sinful nation. They held a council to determine what was to be done, and where they should seek help to prevent or repel the cruel and frequent incursions of the northern nations; and in concert with their King Vortigern, it was unanimously decided to call the Saxons to their aid from beyond the sea, which, as the event plainly showed, was brought about by the Lord’s will, that evil might fall upon them for their wicked deeds.