The wearing of costumes at Halloween may come from the belief that supernatural beings, or the souls of the dead, roamed the earth at this time. The practice may have originated in a Celtic festival, held on 31 October–1 November, to mark the beginning of winter. It was called Samhain in Ireland, Scotland and the Isle of Man, and Calan Gaeaf in Wales, Cornwall and Brittany. The festival is believed to have pre-Christian roots. After the Christianization of Ireland in the 5th century, some of these customs may have been retained in the Christian observance of All Hallows' Eve in that region—which continued to be called Samhain/Calan Gaeaf—blending the traditions of their ancestors with Christian ones. It was seen as a liminal time, when the spirits or fairies (the Aos Sí), and the souls of the dead, could more easily come into our world. It was believed that the Aos Sí needed to be propitiated to ensure that the people and their livestock survived the winter. roman warrior,warrior costume,roman costume,costume roman,the warrior When the dress code calls to go extra this season we've got you covered with this edit of the ultimate in party wear for women. 

From at least the 16th century, the festival included mumming and guising,[10] which involved people going house-to-house in costume (or in disguise), usually reciting verses or songs in exchange for food. 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. Impersonating these beings, or wearing a disguise, was also believed to protect oneself from them. It is suggested that the mummers and guisers"personify the old spirits of the winter, who demanded reward in exchange for good fortune". F. Marian McNeill suggests the ancient pagan festival included people wearing masks or costumes to represent the spirits, and that faces were marked (or blackened) with ashes taken from the sacred bonfire.[9] In parts of southern Ireland, 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. In 19th century Scotland, youths went house-to-house with masked, painted or blackened faces, often threatening to do mischief if they were not welcomed.[10] In parts of Wales, men went about dressed as fearsome beings called gwrachod, while in some places, young people cross-dressed.[10] Elsewhere in Europe, mumming and costumes 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".