The Eve of the Dark Half

In the Celtic calendar, the year was divided into two halves: the bright half, beginning at Beltane in May, and the dark half, beginning at Samhain at the end of October. Samhain — pronounced SAH-win — marked not just a change in season but a genuine threshold in the cosmic order. It was the night when the boundaries between the world of the living and the world of the dead grew thin, when the sídhe (fairy mounds) opened, and when the dead could walk among the living once more.

This was not a holiday in any modern, celebratory sense. It was a time of profound ritual attention — and a time of real spiritual danger.

What Samhain Actually Involved

Our understanding of how ancient Celts observed Samhain comes from a combination of early Irish manuscripts, later folk tradition, and archaeology. While precise pre-Christian practices are difficult to reconstruct with certainty, several themes emerge consistently:

The Great Fires

Communal bonfires were a central feature of Samhain observance. The most famous was the fire lit on the Hill of Ward (Tlachtga) in County Meath, from which other fires across Ireland were said to be kindled. These fires were both purifying and protective — a means of strengthening the community against the dangers of the dark half of the year.

Ancestor Acknowledgement

Food and drink were left out for ancestral spirits. In some traditions, a place was set at the table for deceased family members. The dead were not feared so much as respected and included — Samhain was, in part, a family reunion across the veil.

Divination

The liminal quality of Samhain — its position at a threshold between worlds and between years — made it considered ideal for divination. Nuts were thrown into fires, apple-bobbing (originally a form of fortune-telling) was practised, and young people sought to glimpse the faces of future spouses in mirrors by candlelight.

Disguise and Guising

People disguised themselves — often in frightening or animal costumes — partly to confuse or evade malevolent spirits who walked freely at this time. This practice of guising is the direct ancestor of modern trick-or-treating, carried to North America largely by Irish and Scottish immigrants in the 19th century.

Samhain in Irish Mythology

Many of the most dramatic events in Irish mythology are set at Samhain. The Second Battle of Mag Tuired, in which the Tuatha Dé Danann defeated the Fomorians, occurred at Samhain. The monstrous Fomorian Crom Cruach demanded sacrifice at this time. The hero Fionn Mac Cumhaill slew the fire-breathing spirit Aillen, who emerged from the sídhe each Samhain to burn Tara to the ground.

Samhain, in the mythological imagination, was the night when anything could happen — and usually did.

From Samhain to Halloween

The Christian church, in its characteristic approach to absorbed traditions, reframed Samhain as the vigil of All Saints' Day (All Hallows' Eve — Halloween) and All Souls' Day on 2nd November. The underlying themes — honouring the dead, acknowledging the darkness, marking a great turning — survived the transition remarkably well.

Today, Derry hosts one of the world's largest Halloween festivals, drawing visitors from across the globe to a city that wears its Celtic heritage with particular pride. The irony is fitting: a city defined by its walls celebrating the one night of the year when all walls, between all worlds, are said to come down.

Observing Samhain Today

For those interested in reconnecting with the festival's older roots, several practices translate naturally into a modern context:

  • Light a candle for a departed loved one and speak their name aloud.
  • Prepare a meal using seasonal, local produce — root vegetables, apples, hazelnuts.
  • Spend time outdoors at dusk on the 31st, paying attention to the quality of the air and the sky.
  • Reflect on what you are leaving behind as the year turns — Samhain was always as much about release as it was about fear.