Although now very much associated with a presidential welcome to returning emigrants, placing a lighted candle in your window at Christmas is the traditional way of attracting the Christmas fairy to your door. If he comes, he can bring you good luck. So says folklore expert Bob Curran, author of A Field Guide To Irish Fairies: "The Christmas fairy turns up in the guise of a wayfarer. Christmas is supposed to be the season of love and goodwill, and the fairy comes to test you out," he explains. The idea of the wayfaring fairy is apparently Scandinavian and was brought to Ireland by the Vikings. "It fits in with the Christian myth of our Lord arriving and no room at the inn," he adds.
The fairies are either members of the Tuatha de Danaan or the old pagan gods of the earth, nobody really knows, says Curran. As Christianity spread through Ireland, they became equated with angels: "In north Antrim, people began to believe that the fairies were fallen angels, those who sat on the fence during the great rebellion in heaven and who were thrown out for their indecisiveness."
St Michael, the patron saint of fairies, was said to have interceded with God on their behalf and they were given the dark and remote places of the earth in which to dwell.
Christmas was believed to be the time of the angels, says Curran, when the gates of heaven stood open for the 12 days of Christmas: "All who died, whether sinner or holy person, were admitted into heaven if they were accompanied by an angel." These fallen angel/fairies had a dark side: "If you met them on the road they had the power to take you with them. Some argue that fairies have a great spite against humans because we can enter heaven and they can't. They can only accompany us to the gates." He remembers when he was a boy, growing up in rural Co Down on the edge of the Mourne Mountains 30 years ago, there was a tramp found dead one morning, "probably from exposure" but "it was said that he had been taken by the fairies".
At the time of the solstice the fairies are at their most powerful, he warns, and can be particularly malignant "if you cross them." This can occur quite by accident, as in if you are throwing a basin of dirty water out of the back door late at night and accidentally drench a fairy. A good way of preventing this from happening is to say "Hugitas, ugitas, iskey sollach" ("away, away, dirty water") before you fling out the slops.
The Christmas tree has an interesting past too: "Pagan tree worship took place in Ireland - Moville in Co Donegal means the place of tree adoration in Irish - and in Germany. Human sacrifices were made to trees. In the eighth century, the German Saint Willibrand tried to introduce the tree as a Christian symbol by hanging Christian ornaments from its branches and putting an angel at the top of the tree to sanctify it," says Curran. Eventually it was considered bad luck to have a tree in the house unless it was hung with holy ornaments because "it would bring paganism into the house."
As for Santa Claus, he originates in two fairy characters - Stupbbe Peter and Night Rupert - from 19th-century Germany who were "half animal, half human": "Night Rupert was accompanied by tomtins, nasty little elves who came down the chimney and wakened children in the middle of the night and asked them if they could say their catechism. If they could they were rewarded. If not, they were beaten with chains."
As far back as the ancient Celts, this time of year was associated with "quasi-mystical figures who went about at night rewarding those who had worshipped them during the year and punishing those who hadn't." In spite of Bob Curran's assurances of good luck, you light that candle and usher in that wayfarer at your peril. Who knows if you'll pass the test.
A Field Guide To Irish Fairies by Bob Curran is published by Appletree Press, £7.99 hardback
