Fairies are Gods of the Past
Just as there are deities grown out of tales of fairies, trees, and other natural forces, so to did the deities eventually return to being such beings as people thought less and less about them. Even as lessened beings, however, the deities of old:
“To a considerable degree retain their hold on the faith of the peasant and, at least in outlying districts, maintain a vigorous existence. The Church has waged war against them for centuries and has degraded and disfigured many of them. Although their expression has in many cases become greatly altered, yet their original features may easily be recognized by a careful observer.” (Ralston, 1872)
These deity/fairies manifested themselves as both friendly and unfriendly beings while retaining their close relationship with humans or growing bitter and cruel over time. Byelobog, one of the divinities of the Russians which retained his kind nature, became Bylun, an old man which assists travelers in finding their way out of dark forests and also assists reapers within corn fields. (Ralston, 1872)
In Great Britian there was a former deity who dressed in leaves and would help children lost in the mountains. (Briggs, 1967) Danu, a goddess of the Celtic peoples, became not one but many fairy beings one of which is a hag known as Black Annis which haunts caverns and hills from which she seeks to devour humans. Hills in general it would seem have become the resting places of the gods which had passed on into their fairy forms.
“In a prayer of S. Columba's, (he) begs God to dispel "this host (i.e. the old gods) around the cairns that reigneth."
In Ireland, the divinity of the Tuatha Dé Danann is still recalled. Eochaid O'Flynn (tenth century), doubtful whether they are men or demons concludes, "Though I have treated of these deities in order, yet have I not adored them." Even in later times they were still thought of as gods in exile, a view which appears in the romantic tales and sagas existing side by side with the notices of the annalists. They were also regarded as fairy kings and queens, and yet fairies of a different order from those of ordinary tradition. (Maccullock, 1911)
Many of these deities returned to being simple natural phenomena. The Blue Hag of the highlands, for example, appears to be the personification of winter. She herds deer and fights spring with her staff which freezes the ground. When spring wins, she hides her staff under holly where the grass never grows. (Briggs 1967)
The Tiddy Mun was a fen spirit which caused pestilence and controlled the waters and the mists. Although the people still held affection for him, like all fairies and ancient deities he could be dangerous if he was insulted. Once when parts of the fens were drained, the people had to pacify him with prayers. (Briggs, 1967) That they pacified him with prayers is telling about his general role in the world. In essence, Tiddy Mun brought all the things that the fens were said to bring from the fog to the diseases. Even with all of these problems, people still ultimately love the landscape around them especially when such a landscape makes them unique from their neighbors.
The ocean deities too remained behind continuing to manifest the sea. “Bucca” or “Bucca-Boo” seemed originally to have been a sea god. Fishermen left fish on the sands for Bucca and/or a piece of bread at harvest time along with a few drops of beer.” (Briggs, 1967) As time passed, his role did shift, however, to that of a being which torments children. As we’ve seen, internal duality, that is making the same being good and bad, was common among the old religions of Europe. As time went on the deities’ abilities to do either of these grew less and less until they were left tormenting children.
The lessening of deities became so extreme that Dirra, one of the gods of old, was captured by the Earl of Desmond as a fairy bride after she’d become a simple water nymph. It was not, however, just the Christians who lessened the deities of the peoples they’d conquered or converted. The Romans on conquering Gaul turned many of the local gods into nymphs and naiads when their sacred pools, trees, valleys, etc. were taken over by Apollo. Then as Briton was once more conquered by another religion, these beings were once again lessened to fees, fairies which stand no larger than a child.
Charles Squire maintains that many of the fairy beings of Ireland are the divinities of the pre-Celtic peoples who inhabited that kingdom who were lessened when the Celts invaded. Specifically he states that:
“The leprechaun, who makes shoes for the fairies and knows where hidden treasures are, the Gan Ceanach, or "love-talker" who fills the ears of idle girls with pleasant fancies when to merely mortal ideas they should be busy with their work; the pooka, who leads travellers astray, or taking the shape of an ass or mule, beguiles them to mount upon his back to their discomfiture; the Dulachan, who rides without a head, and other friendly or malicious spirits. Whence come they? A possible answer suggests itself. Preceding the Aryans and surviving the Aryan conquest all over Europe was a large, non-Aryan population which must have had its own gods who would retain their worship, be revered by successive generations, and remain rooted to the soil.” (Maccullock, 1911)
It would seem strange to think that a divine being, a god, could be captured the way a leprechaun is. Forced to become some man’s bride through a simple trick the way many fairies are in legend, or that they should be as feebly petty as to try to “beguile” people to ride them as a means to cause people discomfiture. So if as Charles and MacCulloch maintain these beings as previous gods then would indicate that such beings have been greatly weakened to the point where they become fairies.