The Most Ancient Lives of Saint Patrick/The Life and Acts of St. Patrick/Chapter 170
The Threefold Plague is driven out of Hibernia by Saint Patrick.
And the most holy Patrick applied all his diligence unto the extirpation of this threefold plague; and at length by his salutary doctrine and fervent prayer he relieved Hibernia of the increasing mischief. Therefore he, the most excellent pastor, bore on his shoulder the staff of Jesus, and aided of the angelic aid, he by its comminatory elevation gathered together from all parts of the island all the poisonous creatures into one place; then compelled he them all unto a very high promontory, which then was called Cruachan-ailge, but now Cruachan-Phadruig; and by the power of his word he drove the whole pestilent swarm from the precipice of the mountain headlong into the ocean. O eminent sign! O illustrious miracle! even from the beginning of the world unheard, but now experienced by tribes, by peoples, and by tongues, known unto all nations, but to the dwellers in Hibernia especially needful! And at this marvellous yet most profitable sight, a numerous assembly was present; many of whom had flocked from all parts to behold miracles, many to receive the word of life.
Then turned he his face toward Mannia, and the other islands which he had imbued and blessed with the faith of Christ and with the holy sacraments; and by the power of his prayers he freed all these likewise from the plague of venomous reptiles. But other islands, the which had not believed at his preaching, still are cursed with the procreation of those poisonous creatures. And he converted innumerable evil-doers unto the faith; but many who continued obstinate, and hardened in their perverseness, he destroyed from the face of the earth (as we have already recorded); and from the men of Hibernia, whom he made servants unto the true and living God, prayed he of the Lord that the visions of the demons and their wonted injuries should be driven away; and he obtained his prayer.