Samhuinn (Samhain in Irish) is the time of the ‘little sun’. Astronomically, it is a time when the seven stars that form the Pleiades rise at sunset, and the harvest is in. Seasonally, all plants and berries are gathered from the hedgerows, and cattle have been driven back to winter inside the villages.

In Scotland, many folk traditions date back to pre-Christian Celtic ancestors. Samhuinn contrasted with the festival of Bealltainn six months earlier in the year when folk celebrated the return of the ‘big sun’ and the fertility of the Earth. Fire was sacred to the Celts and part of both celebrations.

At both Bealltainn and Samhuinn, ritual ‘neid fires’ were also made. This involved the extinguishing of all the villagers’ hearth fires. Two special sticks were then rubbed together to raise the sacred fire. From this neid fire, hot embers, called clavies, were then taken to relight all the hearth fires.

The modern Hallowe’en is a blending of Gaelic myth regarding the supernatural and the sacred fire, and the early Christian beliefs of the dead and the day commemorating departed saints. This holiday began to truly take shape in the Medieval period. It is from this time that ‘trick or treat’ or ‘guising’ started. ‘Galoshins’ plays, irreverent social satires with set characters, were performed throughout Scotland. In them, youngsters wearing masks or “guises”, carrying turnip lanterns and causing all sorts of mischief, often took part.

The Reformation in the 16th century brought a fervent attempted to ‘stamp out the superstitious practices’; by the 18th century, many had disappeared.

In modern times, there have been movements to rekindle Scotland’s traditions and Celtic myths. Edinburgh’s Beltane Fire Society, which presents its Samhuinn procession on October 31 to mark the onset of winter,  runs from the Lawnmarket to Parliment Square. The Fire Society also performs the fire festival of Bealltainn on Calton Hill.

http://www.electricscotland.com/history/scotsman/halloween.htm