From at least the 16th century,[54] the festival included mumming and guising in Ireland, Scotland, the Isle of Man and Wales.[55] This involved people going house-to-house in costume (or in disguise), usually reciting verses or songs in exchange for food.[55] It may have originally been a tradition whereby people impersonated the Aos Sí, or the souls of the dead, and received offerings on their behalf, similar to the custom of souling (see below). Impersonating these beings, or wearing a disguise, was also believed to protect oneself from them.[56] It is suggested that the mummers and guisers "personify the old spirits of the winter, who demanded reward in exchange for good fortune".[57] In parts of southern Ireland, the guisers included a hobby horse. A man dressed as a Láir Bhán (white mare) led youths house-to-house reciting verses—some of which had pagan overtones—in exchange for food. If the household donated food it could expect good fortune from the 'Muck Olla'; not doing so would bring misfortune.[58] In Scotland, youths went house-to-house with masked, painted or blackened faces, often threatening to do mischief if they were not welcomed.[55] F. Marian McNeill suggests the ancient festival included people in costume representing the spirits, and that faces were marked (or blackened) with ashes taken from the sacred bonfire.[54] In parts of Wales, men went about dressed as fearsome beings called gwrachod.[55] In the late 19th and early 20th century, young people in Glamorgan and Orkney cross-dressed.[55] Elsewhere in Europe, mumming and hobby horses were part of other yearly festivals. However, in the Celtic-speaking regions they were "particularly appropriate to a night upon which supernatural beings were said to be abroad and could be imitated or warded off by human wanderers".[55] From at least the 18th century, "imitating malignant spirits" led to playing pranks in Ireland and the Scottish Highlands.[55] Wearing costumes and playing pranks at Halloween spread to England in the 20th century.[55] The "traditional illumination for guisers or pranksters abroad on the night in some places was provided by turnips or mangel wurzels, hollowed out to act as lanterns and often carved with grotesque faces".[55] By those who made them, the lanterns were variously said to represent the spirits,[55] or were used to ward off evil spirits.[59][60] They were common in parts of Ireland and the Scottish Highlands in the 19th century,[55] as well as in Somerset (see Punkie Night). In the 20th century they spread to other parts of England and became generally known as jack-o'-lanterns.[55]

Christian influence
Today's Halloween customs are also thought to have been influenced by Christian dogma and practices derived from it. Halloween is the evening before the Christian holy days of All Hallows' Day (also known as All Saints' or Hallowmas) on 1 November and All Souls' Day on 2 November, thus giving the holiday on 31 October the full name of All Hallows' Eve (meaning the evening before All Hallows' Day).[61] Since the time of the primitive Church,[62] major feasts in the Christian Church (such as Christmas, Easter and Pentecost) had vigils which began the night before, as did the feast of All Hallows'.[63] These three days are collectively referred to as Allhallowtide and are a time for honoring the saints and praying for the recently departed souls who have yet to reach Heaven. All Saints was introduced in the year 609, but was originally celebrated on 13 May,[64] the same date as Lemuria, an ancient Roman festival of the dead. In 835, it was officially switched to 1 November, the same date as Samhain, at the behest of Pope Gregory IV.[64] Some suggest this was due to Celtic influence, while others suggest it was a Germanic idea,[64] although it is claimed that both Germanic and Celtic-speaking peoples commemorated the dead at the beginning of winter.[65] It may have been seen as the most fitting time to do so, as it was when the plants themselves were 'dying'.[65][64] It is also suggested that the change was made on the "practical grounds that Rome in summer could not accommodate the great number of pilgrims who flocked to it", and perhaps because of public health considerations regarding Roman Fever – a disease that claimed a number of lives during the sultry summers of the region.[66]

Happy hallowen (it's really mean all saints) for those who don't understand Latin