De Vita Germani 12-27

12 At the same time [AD 429] an embassy sent from Britain made it known to the bishops in Gaul that the Pelagian heresy had taken hold of the people far and wide in their land, and that they should send help to the Catholic faith as soon as possible. For this reason a large assembly was summoned, and by a unanimous decision they solicited with their prayers those two brilliant lights of religion, Germanus and Lupus, both apostolic priests ... (They cross to Britain despite adverse weather conditions and bolster up the Catholic faith) ...

14. ... The authors of the evil doctrine maintained a low profile and like malign spirits groaned at the loss of people who escaped their clutches. Finally, after much thought they deigned to enter the lists. Forth they came, gleaming with their riches, brilliantly clothed, and surrounded by much flattery. They preferred to submit to the hazard of public debate rather than to incur the ignominy of silence among the people they had subverted, lest they seem to have damned themselves by keeping quiet. A truly vast multitude of people was invited, along with their wives and children, and assembled there. The people were present as observers and judges while the opposing sides presented vastly differing appearances: on one side divine authority, on the other human presumption; on one side faith, on the other heresy; on one side Pelagius as teacher, on the other Christ. The blessed priests first gave their opponents the opportunity to state their case; this took up much time to no purpose and filled the ears with nought but empty words. Then the venerable bishops poured forth torrents of their eloquence along with thunderings from the apostles and evangelists. Their own speech was interspersed with scriptural passages and they followed their own weighty declarations with written testimony. Vanity stood convicted; heresy refuted ... (Germanus cures the blind daughter of a man said to exercise the ‘power of a Tribune’. They then go to the shrine of St Alban).

16 With the damnable heresy curbed and its authors refuted and with the minds of all restored to calm by the purity of the faith, the priests sought out the blessed martyr Alban, intending to give thanks to God through the saint ... (Germanus is hurt in a fall, and while he is resting in a house the buildings in the vicinity catch fire. However, while the flames consume all around, the building containing Germanus is untouched. Following this, Germanus cures many sick people and is eventually himself cured by miraculous means) ...

17 In the meantime, the Picts and Saxons joined forces and made war on the Britons, whom the same need had brought together into the camp, and since in their fear the Britons judged themselves not quite equal to the enemy, they sought the help of the holy bishops. They for their part hastened their promised coming and instilled such a feeling of security and confidence that one would have thought a great army had arrived. And so it was that with these apostolic leaders there was Christ militant in the camp. The forty days of Lent were also at hand, which the presence of the priests made all the more holy in as much as the people, taught by daily preaching, eagerly flocked to receive the grace of baptism. For most of the army sought the water of salvation ... With the festival of Easter over, the greater part of the army, fresh from their baptism, prepared to take up their arms and get ready for war. Germanus declared himself their leader in battle, picked out those lightly armed, scouted the surrounding countryside and noticed a valley, surrounded by lofty mountains, in that quarter where he expected the arrival of the enemy. Here he assembled his new army with himself as its leader.

18 Soon there came upon them the fierce host of the enemy, which those lying in ambush saw approaching. Then suddenly Germanus, the standard-bearer, exhorted and commanded all his men to repeat his words together in a loud voice, and with the enemy in their negligence confident that their arrival was unexpected, the priests three times cried out “Alleluia”. All replied in unison, and the close confines of the mountains re-echoed the cry they raised. The enemy forces were struck with terror and fear that both the rocks around them and the very vault of heaven threatened to overwhelm them. They scarce believed the swiftness of their feet sufficient (to escape) the terror hurled upon them. They fled in all directions, cast aside their weapons, were glad to have saved their unprotected bodies from the danger ... (Germanus and Lupus return to the continent) ...

25 In the meantime [c. AD 446] it was reported from Britain that once again the perversity of Pelagianism was spreading through the agency of a few people. Once more the entreaties of all the priests are conveyed to that most blessed man, that he defend the cause of God which earlier he had championed. Speedily he agreed to their request since he delighted in exertion and gladly devoted himself to Christ ... Together with Severus, a bishop of singular holiness, he put to sea led only by the inspiration of Christ. The elements conspire to produce a smooth crossing ... (Their arrival is followed by a miracle of healing which confirms the Britons' belief in Catholic doctrine) ...

27 ... He then turned to preach to the people about repentance for their transgressions, and by universal assent the authors of that enormity, condemned to be banished from the island, were brought to the priests for conveyance into the depths of the continent, so that the land might have the pleasure of being rid of them, and they the profit of their repentance.