The night between years
Every year on October 31st, porches glow with carved pumpkins, children knock on doors asking for sweets, and costumes take over streets across the world. For most people, that is simply Halloween. However, the holiday we recognise today is not one single ancient ritual that survived unchanged. It is the result of centuries of blending, borrowing and reinvention.
To understand it, we have to go back to a festival called Samhain.
1. Samhain: A Celtic marker of the turning year
Long before Halloween, many Gaelic-speaking communities across Ireland, Scotland and the Isle of Man marked Samhain (pronounced roughly "SOW-in").
What historians know with confidence is that Samhain fell around the end of October and was one of the major turning points of the Celtic year. It marked the transition from the harvest season to the darker, colder half of the year. For largely pastoral and agricultural communities, that transition carried real weight. Livestock were brought in from summer pastures, stores were counted for winter, and work shifted accordingly.
Folklore surrounding Samhain spoke of a time when the boundary between this world and the "Otherworld" grew thin. Tales of spirits, fairies (Aos Sí) and wandering entities appear in Irish and Scottish traditions. However, it is important to draw a line between what is attested in early Irish texts and later Victorian retellings. Many of the spookier, universal "all ghosts roam free" ideas are exaggerated compared to the more grounded, regionally varied beliefs recorded by folklorists.
2. All Saints and All Souls: Christianisation of the date
By the 8th and 9th centuries, the Christian Church was active across much of the Celtic world. A key turning point came with Pope Gregory III (8th century) and the wider observance of All Saints' Day on November 1st, with All Souls' Day following on November 2nd.
Scholars widely agree that the church did not simply "replace" Samhain overnight. Instead, it offered a Christian framework for existing customs. The evening of October 31st became known as All Hallows' Eve (the eve of All Hallows/All Saints). Over time, local folk practices and church observances bled into one another across Ireland, Scotland and parts of Wales.
This is the true origin of the name "Halloween". It is a contraction of "All Hallows' Eve", not a direct anglicisation of Samhain itself.
3. Guising, souling and the roots of going door to door
One of the strongest links to trick-or-treat can be found in older British and Irish traditions.
In parts of Ireland and Scotland, people took part in guising — dressing up in disguise, going from door to door, reciting a verse, telling a story or performing a short act in exchange for food. Meanwhile, in England, the medieval practice of souling saw the poor go door to door on All Souls' Eve offering prayers for the dead in return for soul cakes.
These were separate customs with different motivations, but they share the same core: disguise, verses, and a request for treats in return for an act. This is far closer to the documented history than the oft-repeated claim that trick-or-treat is a direct, unbroken Samhain tradition.
4. From turnips to pumpkins
Long before plastic jack-o'-lanterns filled shelves, people in Ireland and Scotland carved faces into turnips, mangolds and potatoes and placed a candle inside. These were often used to ward off unwanted spirits, or simply as lanterns for guisers on dark autumn nights.
When Irish and Scottish immigrants brought these traditions to North America in large numbers during the 19th century, they found an abundance of pumpkins. Softer, larger and easier to carve, the pumpkin quickly became the lantern of choice. By the early 20th century, the jack-o'-lantern had shifted away from its older superstitious associations and firmly into the realm of seasonal decoration.
5. How trick-or-treat became an American tradition
The modern version of trick-or-treat took shape in the United States, not the ancient Celtic world. Community-based "trick-or-treating" was promoted in the 1920s and 30s as a way to curb rowdy Halloween pranks, and it exploded in popularity after World War II as suburbs grew and neighbourhoods became ideal for it.
By the 1950s, it had been cemented as the default Halloween activity for children across much of America. From there, thanks to film, television and eventually the internet, it spread back across the globe and is now observed in many countries to varying degrees.
The real story
Halloween is a palimpsest. The calendar date comes from the Christian observance of All Hallows' Eve. The doorway to the "Otherworld" belongs more to Gaelic folklore than to any universal pan-Celtic doctrine. The act of going door to door comes from guising and souling. The carved lantern comes from the turnip, not the pumpkin. And trick-or-treat itself is overwhelmingly a 20th-century American standardisation.
None of this makes the holiday any less fun. In fact, its strength is exactly that: a festival built by layering. What we celebrate on October 31st is the end result of that layering — a blend of ancient, medieval, immigrant and modern influences that evolved over centuries to become the Halloween we know today.
Sources
- Hutton, Ronald. The Stations of the Sun: A History of the Ritual Year in Britain. Oxford University Press, 1996.
- MacCulloch, J.A. The Religion of the Ancient Celts. T. & T. Clark, 1911.
- Simpson, Jacqueline & Roud, Steve. A Dictionary of English Folklore. Oxford University Press, 2000.
- Ó hÓgáin, Dáithí. The Lore of Ireland: An Encyclopaedia of Myth, Legend and Folklore. Boydell Press, 2006.