Samhain and the Celtic Roots of Halloween
Samhain (known in Old Irish as Samain) was a major seasonal festival in early Ireland, marking the end of summer and the beginning of winter. Ancient Celts believed the boundary between the physical world and the Otherworld thinned during Samhain, allowing spirits, ancestors and fairies to cross over. It fell around 1 November, but the festival began on the night before, the eve that became Halloween.
Tlachtga (Hill of Ward), with its four concentric banks, in Ireland's Ancient East.
Honouring Ancestors and Welcoming the Winter
In later Irish folklore and Halloween traditions, celebrations centred on remembering the dead, welcoming ancestors and seeking protection from harmful spirits. Food was set aside for departed family members, while disguises and masks became associated with concealing one's identity from supernatural visitors.
Bonfires, feasting and the gathering of communities marked the changing season. Sharing food expressed both hospitality and care for those in need.
From Samhain to Halloween
The Christian calendar also honoured the dead through All Saints' Day, or All Hallows, on 1 November, followed by All Souls' Day on 2 November. The evening before All Hallows became known as All Hallows' Eve, eventually shortened to Halloween.
During the 19th century, particularly during and after the Great Famine of the 1840s, Irish emigrants carried their Halloween customs to America. There, these traditions developed alongside other seasonal celebrations. Pumpkin carving became a familiar feature, adapting the Irish tradition of carving lanterns from turnips.
Samhain at Tlachtga and Tara
Two hills in the Boyne Valley have strong associations with Samhain: Tlachtga, now known as the Hill of Ward, and the Hill of Tara. Later historical accounts connect Tlachtga with a great ceremonial fire at Samhain, while Tara features prominently in stories of gatherings, kingship and encounters with the Otherworld.
A Connection to an Older Seasonal Calendar
The entrance passage of the Mound of the Hostages on the Hill of Tara is aligned with the rising sun around early November and early February, close to the festivals of Samhain and Imbolc. Built approximately 5,000 years ago, this Neolithic monument suggests that these seasonal turning points held significance long before the Celtic traditions recorded in later Irish sources.
The earthworks and prehistoric monuments of the Hill of Tara.
Samhain in Irish Mythology and Folklore
Adapted from Tlachtga: Celtic Fire Festival by John Gilroy.
A Night Between Two Worlds
Samhain marked a turning point in the year, a threshold between the old season and the new. In the imagination of Irish storytellers, it was a moment suspended in time, when ordinary boundaries loosened and the living might encounter visitors from the Otherworld.
As the days shortened and winter approached, the fading strength of the sun gave fire a powerful symbolic role. The flames at Tlachtga answered the gathering darkness when the natural world seemed to retreat. John Gilroy's interpretation also connects this imagery with Mog Ruith, a figure associated with solar symbolism.
Ghosts, fairies and other mysterious beings filled the stories of this night. Some came as welcome ancestors, while others were unsettling visitors best avoided. Among the figures associated with the realm of the dead was Donn.
Donn and the Otherworld
Donn appears in the story of the Milesians, the mythical ancestors of the Gaels. After reaching Ireland and approaching Tara, the newcomers were required to withdraw beyond nine waves from the shore. A great storm scattered their fleet, and Donn was among those who drowned.
His dwelling became known as Tech Duinn, the House of Donn, commonly identified with Bull Rock off the Beara Peninsula in County Cork. In Irish tradition that remote island gathered the dead and opened a gateway to the Otherworld.
An ancestral figure receiving the dead gives Donn a special place in Irish mythology, because death could be imagined as a return to the house of an ancestor and so to the origins of the people. His name is often translated as "brown", which suits the shadowy realm beyond ordinary life.
Later folklore tells of strange boats passing towards the island at night and voices calling the names of those arriving, bringing the Otherworld close to fishermen and coastal communities. In Christian retellings the island could also become a place where troubled souls lingered before their final journey.
Seen through these traditions, Samhain is more than the beginning of winter. It is a night when the world of the living opens to ancestors, gods, fairies and the dead.
Sunlight in the Mound of the Hostages on the Hill of Tara around Samhain.
Bonfires and Household Traditions
The great fire at Tlachtga was one of the most striking traditions associated with Samhain. Accounts describe household fires being extinguished before a communal flame was kindled, from which other fires could be relit. The story gives the hill a central place in the celebration and makes the return of light a shared act of renewal.
In that picture, the interval of darkness belongs to the wandering dead. When the new fire blazes, warmth and order return. The communal bonfire expresses the public celebration, while the rekindled hearth brings the festival into the family home.
Ancestors were welcomed with food and a place beside the fire. A flame might be left burning in the grate so that returning spirits could warm themselves. Even when these visitors were thought to be friendly, going to bed early was a comfortable way to leave them undisturbed.
Other stories gave the returning dead a less gentle character. An offering could secure goodwill, while neglect might invite bad luck in the year ahead. The exchange of a gift for protection echoes the playful bargain of modern trick-or-treating, though that custom grew from more than one source.
The uncertainty of the night extended to the landscape. Boundaries between neighbouring fields, stiles, bridges and crossroads were places where spirits might be encountered. Burial grounds held a particular dread. For an unwary traveller, the familiar countryside could become strange, making the warmth of home all the more inviting.
Divination at Halloween
A night when ordinary boundaries seemed to weaken was also a time to look into the future. Halloween fortune-telling ranged from cheerful household games to unsettling encounters, and food or familiar objects could forecast marriage, prosperity and the year ahead.
One story told of a watcher standing in a church porch at midnight to see the spirits of those destined to die in the coming year. The worst fear was recognising oneself among them. Other traditions described looking into a mirror for a glimpse of a future husband, though a more frightening face might appear instead.
Graveyard tales offered another route beyond everyday life. Walk three times around the graves at midnight and you might learn the future, or meet the devil. In Gilroy's reading the sunwise turning and darker Christian imagery point to older ritual themes woven into later folklore.
Samhain promised knowledge, though approaching the unknown always carried a price in the storyteller's imagination.
Tlachtga on the Hill of Ward, a site associated with Samhain fire traditions.
Samhain in Irish Stories
Early Irish literature repeatedly chooses Samhain as the setting for remarkable events. In stories of the Fianna, it marks the end of the fighting and hunting season, when the warriors enter winter quarters until summer returns at Beltane.
Fionn mac Cumhaill comes to Tara at Samhain, where his encounter with the fire-breathing Aillén becomes one of his defining adventures. Lugh arrives at Tara as an extraordinary visitor to a royal gathering. Stories of Medb (Maeve) and Cú Chulainn draw on the season’s atmosphere of conflict and uncertainty.
The Second Battle of Mag Tuired, associated with Moytirra near Lough Arrow in County Sligo, is linked with Samhain in Irish tradition. This is distinct from the First Battle of Mag Tuired, associated with the Cong area near the Mayo-Galway border.
For the writers of these tales, Samhain was when the extraordinary felt possible. Royal halls, remote islands and familiar hills became meeting places between human life and the Otherworld. Fire, feasting and remembrance from that night still echo in Halloween.