In many ways, the Celtic world was the opposite of ours. Their day started at twilight (which is why their festivals began on the "eve" of the day itself). They seem to have felt that life began with death - so that debts which had been accrued in this life could be repaid in the Otherworld (i.e. after death). And while the Celtic year was quartered by regular festivals, the two major festivals of Beltane (the "Fires of Beli" which burned in early May) and Samhain stood as the twin poles of the year. Beltane ushered in the summer. Samhain marked the end of summer. It was, essentially, the Celtic New Year.
The Celtic year, then, began at the threshold of winter (in contrast to the Julian Calendar, named after Julius Caesar, which set March 25th as the start of the year). Just as the Celtic day began with night, and life began with death, so the new year began with the death of the old.
Samhain (pronounced "SOW-un" or "SAH-vun") was one of two calendrical gateways, the other being the "May-Day" festival of Beltane. Both were essentially Moon festivals and both featured large bonfires. In Britain, the bonfire element of Samhain has been retained, although the date was moved when, in 1606, an Act of Parliament determined that the people should celebrate the foiling of the Gunpowder Plot each year on the fifth day of November. Thus, Bonfire Night - as it is known in the United Kingdom - is really a sort of detached Samhain celebration, and the effigies of Guy Fawkes which are traditionally burned on the bonfires compare with the diabolical images associated with Samhain or Halloween: the hollowed-out pumpkins (or turnips, in Scotland) representing the spirits which are honoured at the end of summer.
But Samhain's associations with the agricultural round and, in particular, the end of the harvest season, are easiest to recognise in terms of grain.
The folk character of John Barleycorn represented the spirit of the grain which grew through the summer months. He was, in essence, the solar hero - the "god" who flourished as the Sun grew more powerful, only to decline from Midsummer onwards. His feminine counterpart (the Moon) underwent a similar sort of journey through the course of the year: she began as the youthful Maiden at Imbolc (early February), becoming the Flower Bride of Spring at Beltane and the fruitful Mother-figure at Lughnasadh (early August), before manifesting herself as the aged Crone or Hag at Samhain. Together, the male and female principles were engaged in a sort of cyclical dance: she grew old as the year grew old; he rose with the corn, only to be cut down at harvest time - just as the Sun became stronger, and then weaker.
The corn harvest therefore represented something of a crisis for the solar hero, the John Barleycorn figure who - though he would rise again - was doomed to be cut down in his prime. His sacrifice was made manifest in the fields, both by the deaths of any animals which were discovered amidst the corn, but also by the poppies which grew in the cornfields. A perennial symbol of sleep, and the dream-state of death, the blood-red poppy came to represent the "blood-sacrifice" of the corn-god during the grain harvest and those warriors who had fallen during the battle season of summer.
The sense of facing both ways - backwards and forwards, remembering and anticipating - remains in our modern New Year, which takes place at the beginning of January (from the Roman god Janus, who faced two ways). At Samhain, this implied a liminal time, a moment when time itself was suspended between past and future. And just as at that other turning-point of the year - Beltane - this liminal moment was seen as an occasion when the veil between worlds was exceedingly thin. The spirits of the ancestors and those of the natural environment were deemed to have been especially active at this time, and liable to revisit the living. Samhain provided a sort of portal or gateway for these spirits to return, and so in honouring the (past) sacrifice of the corn-spirit and the (present) sacrifice of the Martinmas cattle, the living also honoured those who had gone before them into the Otherworld. It became a festival of the ancestors, a Celtic Day of the Dead, a time to remember the ancestral and the elemental spirits at the very moment when the world turned from summer to winter.
However, for a real taste of what Samhain traditionally meant, we must bear in mind a more recent change in the calendar. The Gregorian Calendar (named after Pope Gregory XIII) was introduced in 1582, but it was not adopted in Britain until 1752. By then, the difference between the "Old Style" Julian Calendar and the "New Style" Gregorian equivalent was 11 days. When the New Style calendar was introduced in Britain, Wednesday, September the 2nd 1752, was immediately followed by Thursday, September the 14th. People rioted, fearing that nearly two weeks of their lives had been taken from them!
But the change in the calendar meant that the old festivals shifted. Imbolc - the Celtic festival which took place around February the 2nd - now fell on February 14th (which is why we celebrate true love on "St Valentine's Day"). The "games of Lugh", which were celebrated at Lughnasadh - August 1st - became the "Glorious Twelfth" and the start of the grouse-shooting season. The Midwinter festival of Yule now fell twelve days later on January 1st, or "Hogmanay", as it is known in Scotland.
Samhain also slipped from its traditional date. We have already seen that some of the Samhain traditions - in particular, the slaughter of cattle to provide meat for the winter - became associated with St Martin's Day, or November the 11th. The bonfires of Samhain now burn, thanks to an Act of Parliament, on November the 5th (although a visit to Northern Ireland should show that the night of bonfires and "false faces" is still celebrated there on October 31st). But early in the 20th century, a historical accident reinstated much of the old spirit of Samhain.
When the Armistice brought an end to the First World War, the date of November 11th became Remembrance Day, and the "Doomed Youth" which was cut down on the Western Front was commemorated in much the same way as the dead were traditionally honoured at Samhain. Even more telling, the Flanders poppy became the essential symbol of remembrance - just as it had previously signified the sacrifice of John Barleycorn at harvest time.
Though, in our overly commercial age, we tend to celebrate the traditions of Samhain at Halloween - with mischief and trickery, treats representative of summer's bounty, and images of the ghosts and goblins which are loosed upon the living world at this time of year - the "real" Samhain would fall today on Remembrance Day, our contemporary "Day of the Dead".