The festival of Samhain celebrates the end of the “lighter half” of the year and beginning of the “darker half”, and is sometimes[2] regarded as the “Celtic New Year”.
The ancient Celts believed that the border between this world and the Otherworld became thin on Samhain, allowing spirits (both harmless and harmful) to pass through. The family’s ancestors were honoured and invited home 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.