Halloween — 31 October — is now a global night of costumes and candy, but its roots run back more than 2,000 years to an ancient Celtic festival. Here's the real history of how Samhain became Halloween.
For the date and modern traditions, see Halloween 2026 or the Halloween holiday page.
It started with Samhain
Halloween's origin is the ancient Celtic festival of Samhain (pronounced "sow-in"), marking the end of the harvest and the start of winter — the "darker half" of the year, around 1 November.
The Celts believed that on the night before, 31 October, the boundary between the living and the dead grew thin, allowing spirits to cross over. People lit bonfires and wore costumes and disguises to ward off — or blend in with — wandering spirits.
How Samhain became "Halloween"
As Christianity spread across the Celtic world, the church placed two feast days nearby:
- All Saints' Day (All Hallows) on 1 November
- All Souls' Day on 2 November
The evening before All Saints' Day became "All Hallows' Eve" — eventually contracted to "Hallowe'en," then Halloween. The older Samhain customs blended with the new Christian observances.
Where the traditions come from
- Trick-or-treating: descends from medieval "souling" (the poor going door to door offering prayers for the dead in exchange for "soul cakes") and Scottish/Irish "guising" (costumed children performing for treats).
- Jack-o'-lanterns: from the Irish legend of "Stingy Jack," who roamed with a carved turnip lantern. Irish immigrants to America switched to the larger, easier-to-carve pumpkin.
- Costumes: echo the Samhain practice of disguising oneself from spirits.
- The colours orange and black: orange for the autumn harvest, black for death and the long winter night.
How it became a global holiday
Irish and Scottish immigrants brought Halloween to North America in the 1800s, where it grew into the candy-and-costume celebration known today. From there it spread back across the world through popular culture, and now blends with local traditions — like Mexico's Day of the Dead (1–2 November).
Quick answers
Where does Halloween come from? From the ancient Celtic festival of Samhain (around 31 October–1 November), later merged with the Christian All Hallows' Eve.
What does "Halloween" mean? It's a contraction of "All Hallows' Eve" — the evening before All Saints' Day (1 November).
Why do we carve pumpkins? From the Irish legend of Stingy Jack and his carved-turnip lantern; immigrants to America adopted the pumpkin.
Where did trick-or-treating come from? From medieval "souling" and Scottish/Irish "guising" — going door to door in costume for food or treats.