Halloween - 31st October
The name itself could have come from "The festival of Samhain", celebrated by the ancient Celts at the end of the "lighter half" of the year and beginning of the "darker half", the Celtic 'New Year'.
They believed that the border between this world and the Otherworld became 'thin' on Samhain, allowing spirits to pass through. The family's ancestors were honoured and welcomed while harmful spirits were warded off.
It is believed that the need to ward off harmful spirits led to the wearing of costumes and masks. Their purpose was to "disguise oneself as a harmful spirit and thus avoid harm"! In Scotland the spirits were impersonated by young men dressed in white with masked, veiled or blackened faces.
Samhain was also a time to take stock of food supplies and slaughter livestock for winter stores.
The practice of dressing up in costumes and begging door to door for treats on holidays dates back to the Middle Ages. Trick-or-Treating resembles the late medieval practice of souling, when the poor would go door to door on Hallowmas, receiving food in return for prayers for the dead on All Souls Day (1st November)