These Christian missionaries appear not to have denied the reality of those powers exercised by the Druids through their earth gods, but to have attributed them to the agency of evil spirits, and to have believed that their gods were demons; and this seems to have called forth the counter-superstition that these old Celtic saints held familiar intercourse with the angels of God, and in their turn received powerful aid from them—a belief which these saints themselves perhaps were not unwilling to recognise. We can see how such a belief would colour mere natural phenomena, and we have perhaps a very striking instance of it in an incident narrated by Adamnan. While Columba, he tells us, was living in Iona, ‘he went to seek in the woods a place more remote from men and fitting for prayer. And there, when he began to pray, he suddenly beheld, as he afterwards told a few of the brethren, a very black host of demons fighting against him with iron darts. These wicked demons wished, as the Holy Spirit revealed to the saint, to attack his monastery and with the same spears kill many of the brethren. But he, singlehanded against innumerable foes of such a nature, fought with the utmost bravery, having received the armour of the Apostle Paul. And thus the contest was maintained on both sides during the greater part of the day; nor could the demons, countless though they were, vanquish him, nor was he able, by himself, to drive them from his island, until the angels of God, as the saint afterwards told certain persons, and those few in number, came to his aid, when the demons in terror gave way.’ On the same day, when the saint was returning ‘to his monastery, after he had driven the devils from his island, he spoke these words concerning the same hostile legions, saying, Those deadly foes who this day, through the mercy of God and the assistance of his angels, have been put to flight from this small tract of land, have fled to Tiree; and there, as savage invaders, they will attack the monasteries of the brethren and cause pestilential diseases, of which many will be grievously ill and die.’[236] We can understand how such a persuasion should, to Columba’s mind, have peopled a dark thunder-cloud with a host of demons preparing to attack his monastery, and converted its flashes of lightning into iron darts; and how when as it passed over to Tiree his prayers brought angels to his assistance—a belief that would be confirmed if, after seeing the thunder-clouds hang over Tiree, he received the news of a sudden outbreak of sickness there. We may compare this incident with the verses attributed to Columba, and believed to have formed the prayer with which he aided his kinsmen at the great battle of Culdremhne:—