Each clan, tribe, or kingdom had its Druids, who, in time of war, assisted their hosts by magic art. This is reflected back upon the groups of the mythological cycle, each of which has its Druids who play no small part in the battles fought. Though Pliny recognises the priestly functions of the Druids, he associates them largely with magic, and applies the name magus to them.[1095] In Irish ecclesiastical literature, drui is used as the translation of magus, e.g. in the case of the Egyptian magicians, while magi is used in Latin lives of saints as the equivalent of the vernacular druides.[1096] In the sagas and in popular tales Druidecht, “Druidism,” stands for “magic,” and slat an draoichta, “rod of Druidism,” is a magic wand.[1097] The Tuatha De Danann were said to have learned “Druidism” from the four great master Druids of the region whence they had come to Ireland, and even now, in popular tales, they are often called “Druids” or “Danann Druids."[1098] Thus in Ireland at least there is clear evidence of the great magical power claimed by Druids.
That power was exercised to a great extent over the elements, some of which Druids claimed to have created. Thus the Druid Cathbad covered the plain over which Deirdre was escaping with “a great-waved sea."[1099] Druids also produced blinding snow-storms, or changed day into night—feats ascribed to them even in the Lives of Saints.[1100] Or they discharge “shower-clouds of fire” on the opposing hosts, as in the case of the Druid Mag Ruith, who made a magic fire, and flying upwards towards it, turned it upon the enemy, whose Druid in vain tried to divert it.[1101] When the Druids of Cormac dried up all the waters in the land, another Druid shot an arrow, and where it fell there issued a torrent of water.[1102] The Druid Mathgen