'Hallowe'en' is a word first recorded in the sixteenth century, the Scottish dialect version of 'All-Hallows-Even'. This means that the day of Hallowe'en, 31 October, is the eve of the Christian feast of All Hallows, or All Saints, dating from the year 1000 and also known in the past as Hallowmas. Although the name 'Hallowe'en' makes no reference to the dead, the night of 31 October is traditionally the time when the living are most likely to meet them - and not only the dead blessed enough to join those hallowed saints. Despite the Christian roots of its name, the traditions of Hallowe'en are closest to the pagan traditions of the ancient world. According to those traditions the spirits of the dead, whether good, bad or indifferent, could be expected to celebrate the brief freedom of this night in any way they saw fit.

The rituals and atmosphere of Hallowe'en owe most to the ancient Celts, though also something to the Roman conquerors who ruled the Celts for four hundred years. For example, apple-bobbing originated from the celebrations of the Roman festival of Pomona, goddess of fruit, seeds and the harvest, celebrated at the beginning of November. But the time we now call Hallowe'en is essentially the Celtic festival of Samhain, during which the old Celtic year gives way to a new one. This is the night when summer ends and the darkness and cold of winter begin to overwhelm the land. It is a time when things begin to die, from the fallen leaves of autumn to the animals that lose the warmth and light of summer.

The Celts found their own explanation for this: they believed that, on the night of Samhain, the borders between the worlds of the living and the dead thinned to the point where mortals and spirits could cross them. This was a night when the dead could walk among the living, and the living could find themselves, without warning, among the dead. If the returned ghosts were good spirits, they could be welcomed without fear to the homes of their descendants; in parts of Ireland to this day an extra place is set at the family table on Hallowe'en night for these visiting spirits. If they were evil, however, they were more likely to cause havoc in the human world, and destroy the crops and provisions being harvested and stored up for winter. Humans could only hope to ward them off by joining them in their trickery, and so they disguised themselves as spirits, wearing costumes or masks, or painting their faces with soot, in the hope that they and their households would be spared the mischief of the wicked ghosts.

Hallowe'en costumes therefore began as an attempt to fool the dead by temporarily becoming one of them. The hollowed-out pumpkins grinning from houses, classrooms and shop windows everywhere from Boston in Lincolnshire to Boston in Massachusetts have a similar purpose. Carving hollowed-out vegetables into lanterns to scare away evil spirits at Samhain gave rise to the legend of Jack O'Lantern. According to this legend, Jack was a wicked Irish blacksmith, whose spirit was condemned to roam the earth without rest after he had bargained his way out of Hell, but found himself denied entry to Heaven also as a punishment for his crimes. As a consolation prize to light his way through the darkness, Satan threw Jack an ember from the fires of Hell - which he placed into a hollowed-out turnip as a makeshift lantern. Why did Jack then carve a face into the turnip? To frighten away other malignant spirits, of course!

When mass emigration to America began in the mid-eighteenth century, from countries such as Ireland and Scotland where Hallowe'en traditions were strong, the pumpkin soon eclipsed other root vegetables as a more colourful addition to the festivities. After all, it was the same deep orange colour as the Samhain bonfires the Celts lit to symbolise their solidarity in the face of growing darkness.

Halloween pumpkins (30400)

Trick-or-Treating, the tradition of children going from house to house on Hallowe'en to collect sweets from their neighbours, also has deeply historical origins. Misbehaving trick-or-treaters sometimes remind us of those marauding Hallowe'en ghosts of Samhain because of their scary costumes, but theirs is actually another tradition of respect for the dead. From the Middle Ages on, people have celebrated holidays at this time of year by dressing up and going for door to door begging for treats. In medieval Britain and Ireland, the Christian tradition of 'souling' was associated with All Hallows' Day and the day after that, All Souls' Day, when people went to their neighbours' houses to offer prayers for the dead in return for food. Their prayers were intended to release the souls of the dead from Purgatory, the often painful 'halfway-house' of purification they had to pass through before they could enter Heaven.

The soulers' cry "Apple, pear, plum and cherry, / Any good thing to make us all merry!" might sound unfamiliar to modern Trick-or-Treaters, out for candy in all its forms. But these children of the past were also after treats, at a time when sweetmeats were scarce. They knew their demands would usually be answered with specially-baked 'soul cakes', spicy round cakes with flat tops decorated by a cross. Each soul cake eaten represented a soul freed from Purgatory.

Traditional soul cakes

Ghost sightings on Hallowe'en tend to be as rare and notable as they are on all other nights. Nonetheless, it is a night when the living and the dead come to meet each other. Whether we carve features into a pumpkin, field trick-or-treaters at the door, or even look nervously over our shoulder in a place we know should be empty, we are meeting the dead - those good, bad or indifferent ones who went before us, freeing souls, fashioning lanterns, and finding their own ancestors in the growing darkness.