Beltane or Beltain is the Gaelic May Day festival. Most commonly it is held on 1 May, or about halfway between the spring equinox and the summer solstice. Historically, it was widely observed throughout Ireland, Scotland, Cornwall and the Isle of Man. In Irish the name for the festival day is Lá Bealtaine in Scottish Gaelic Là Bealltainn and in Manx Gaelic Laa Boaltinn/Boaldyn. It is one of the four Gaelic seasonal festivals—along with Samhain, Imbolc and Lughnasadh—and is similar to the Welsh Calan Mai.
Beltane is mentioned in some of the earliest Irish literature and is associated with important events in Irish mythology. Also known as Cétshamhain (“first of summer”), it marked the beginning of summer and it was when cattle were driven out to the summer pastures. Rituals were performed to protect the cattle, crops and people, and to encourage growth. Special bonfires were kindled, and their flames, smoke and ashes were deemed to have protective powers. The people and their cattle would walk around or between bonfires, and sometimes leap over the flames or embers. All household fires would be doused and then re-lit from the Beltane bonfire. These gatherings would be accompanied by a feast, and some of the food and drink would be offered to the aos sí. Doors, windows, byres and livestock would be decorated with yellow May flowers, perhaps because they evoked fire. In parts of Ireland, people would make a May Bush: typically a thorn bush or branch decorated with flowers, ribbons, bright shells and rushlights. Holy wells were also visited, while Beltane dew was thought to bring beauty and maintain youthfulness. Many of these customs were part of May Day or Midsummer festivals in other parts of Great Britain and Europe.