| Older festival | Samhain, a Celtic festival marking the end of the harvest |
|---|---|
| Christian layer | All Hallows' Eve, the evening before All Saints' Day (fixed to 1 November in the eighth century) |
| Word origin | "Halloween" is a shortened form of "All Hallows' Even" |
| Reached America | Spread widely from the 1840s, with Irish immigration |
| Trick-or-treating ancestor | Souling and guising, door-to-door customs recorded in medieval Britain and Ireland |
| Halloween 2026 | Saturday, 31 October 2026 |
Last updated: 28 August 2026
Where the word "Halloween" comes from
The name is a contraction. Christians in the medieval period called 1 November "All Hallows' Day" — "hallow" being an old word for a holy person or saint — and the night before it "All Hallows' Even." Said quickly over a few centuries, "All Hallows' Even" wore down to "Hallowe'en" and eventually "Halloween." So the name itself is entirely Christian in origin, even though much of what happens on the night is not.
Samhain, the festival behind the date
Long before anyone called it Halloween, the Gaelic-speaking peoples of Ireland, Scotland and the Isle of Man marked the turning of the seasons with a festival called Samhain (roughly pronounced "sow-in"), held around 31 October and 1 November. It sat at the midpoint between the autumn equinox and the winter solstice, marking the end of the harvest and the start of the colder, darker half of the year.
Samhain is often described as the "Celtic New Year," and that idea fits the timing well — an ending giving way to a beginning. It's worth knowing, though, that no surviving ancient text says outright that the Celts marked a New Year on this date. The label became popular through Victorian-era scholars rather than through direct evidence, so it's best treated as a long-standing tradition rather than a settled historical fact.
What does have wide agreement among historians is that Samhain was seen as a liminal time: a night when the boundary between the world of the living and the world of the dead was thought to grow thin, allowing spirits to cross over. Communities lit bonfires, and some traditions describe people wearing disguises, possibly to blend in with wandering spirits or to ward them off. Those two threads — fire and disguise — are the clearest line running from Samhain to the costumes and jack-o'-lanterns of today.
How the Church calendar met the old festival
Christianity arrived in Celtic lands over the following centuries, and the Church, rather than trying to erase existing festivals outright, often layered its own holy days on top of them. All Saints' Day is a case in point: it was originally kept on 13 May, honoring Christian martyrs, but in the eighth century Pope Gregory III moved the observance to 1 November when he dedicated a chapel in Rome to all the saints. Some historians think the new date was chosen deliberately to overlap with Samhain and the other harvest festivals already being celebrated across Europe at that time of year; others see it as coincidental. Either way, from that point on, the eve of Samhain and the eve of All Saints' Day were the same night, and the two traditions were never fully separated again.
A companion feast, All Souls' Day on 2 November, was added later to pray for the souls of the dead more broadly. Together, the three days from 31 October to 2 November became known as Allhallowtide.
Halloween crosses the Atlantic
Halloween had a smaller, more scattered presence in colonial America, largely because the Puritan-influenced colonies of New England discouraged festivals with pagan or Catholic associations. That began to change through the nineteenth century, and it changed decisively in the 1840s, when the Irish Famine drove large numbers of Irish immigrants to the United States. They brought Halloween customs with them, and Scottish immigrants contributed similar traditions of their own. As Irish and Scottish communities settled across American cities, Halloween grew from a regional custom into a celebration recognized nationwide, gradually taking on the community trick-or-treating, costume parties and civic parades familiar today.
Where trick-or-treating comes from
Trick-or-treating's closest documented ancestor is a custom called souling. In medieval Britain and Ireland, poor people and children went from house to house around All Souls' Day, offering to say prayers for the household's dead relatives in exchange for "soul cakes," small spiced cakes marked with a cross. A related custom called guising also developed in Scotland and Ireland, in which children dressed in costume and performed a song, poem or trick at each house in exchange for food, fruit or coins. Both customs travelled to North America and gradually merged, over the early twentieth century, into the door-to-door candy collecting known today.
The Jack-o'-lantern
The carved pumpkin also has an older and stranger story behind it, rooted in Irish folklore about a trickster called Stingy Jack who is said to have outwitted the Devil and ended up wandering the earth with nothing but a burning ember for light. Irish immigrants originally carved their lanterns from turnips and swedes; pumpkins, native to the Americas, became the material of choice once the tradition took hold in the United States. We've told the full story, with a carving guide, on our Jack-o'-lantern page.
Halloween today
What began as a Celtic marker of the turning seasons, folded into a Christian holy day and reshaped again by immigrant communities in America, is now one of the most widely celebrated nights of the year for children: costumes, trick-or-treating, carved pumpkins and community parties, with the older, stranger layers of the story mostly kept for anyone curious enough to go looking for them.
Common questions about Halloween's history
Is Halloween originally a Celtic or a Christian holiday?
Both traditions feed into it. The date and several customs trace back to the Celtic festival of Samhain, while the name Halloween comes from the Christian observance of All Hallows' Eve, the evening before All Saints' Day. Historians generally see modern Halloween as a blend of the two rather than a direct descendant of either one alone.
Was Samhain really the Celtic New Year?
It is often called that, and the timing fits the end of the harvest and the start of the darker half of the year. But historians note there is no ancient text that clearly states the Celts marked a New Year on this date, so the label is best treated as a widely used tradition rather than a proven fact.
Why is Halloween on 31 October?
31 October is the evening before All Saints' Day, which the Catholic Church fixed on 1 November in the eighth century under Pope Gregory III. That evening, All Hallows' Eve, later shortened to Halloween. The date also lines up with Samhain, the Celtic festival marking the end of the harvest.
When is Halloween 2026?
Halloween 2026 falls on Saturday, 31 October 2026, since Halloween is always celebrated on 31 October regardless of the day of the week.
How did trick-or-treating start?
Its closest ancestor is souling, a custom recorded in medieval Britain and Ireland in which poor people went door to door around All Souls' Day offering prayers for the dead in exchange for small cakes. Related door-to-door customs, including guising in costume, continued in Scotland and Ireland and travelled to North America with Irish and Scottish immigrants, where they merged into the trick-or-treating known today.
When did Halloween become popular in America?
Halloween had been celebrated in a scattered, regional way in America before the 1840s, but large-scale Irish immigration during and after the Irish Famine of that decade spread Halloween customs more widely, and the holiday grew into a mainstream, community-wide celebration through the late nineteenth and early twentieth centuries.