The Origins of Halloween

Samhain: the Celtic new year

Long before anyone said "trick or treat," the Gaelic peoples of Ireland, Scotland and the Isle of Man marked the turn of the year with Samhain. Falling around November 1, it divided the bright half of the year from the dark half. Cattle came down from summer pastures, the last crops were stored, and communities prepared for winter.

Irish tales written down by medieval monks describe Samhain as a time of great gatherings, feasting and, importantly, of contact with the otherworld. On this night the sídhe : the fairy mounds : were said to open, and spirits, fairies and the dead could pass more easily among the living. People lit bonfires on hilltops, and in some later traditions households let their hearth fires go out and relit them from the communal fire.

Much of what is popularly written about Samhain is speculation, and historians are careful here. There is no reliable evidence for human sacrifice or for a "Celtic god of the dead" named Samhain : that idea came from 18th-century writers and has been repeated ever since. What we can say with confidence is that late autumn was a liminal moment: the harvest was in, the nights were lengthening, and people believed the world of spirits pressed close.

Myth check: Samhain is the name of the festival, not a deity. The "lord of the dead" story is a modern invention that has no support in early Irish sources.

All Saints and All Souls: the Church's calendar

Christianity reached Ireland in the 5th century, and with it came a different calendar of holy days. In the 8th century Pope Gregory III dedicated a chapel in St. Peter's Basilica to all the saints on November 1, and in the following century Pope Gregory IV extended the feast across the Western Church. Around the year 1000, the monastery of Cluny promoted All Souls' Day on November 2, a day to pray for the souls of all the faithful departed.

The overlap with Samhain may or may not have been deliberate : scholars still debate it : but the effect was unmistakable. The first days of November became a season for honoring the dead, and the night before All Saints became All Hallows' Eve. In Scots the phrase contracted to Hallowe'en, the spelling Robert Burns used for his 1785 poem describing the night's fortune-telling games in rural Ayrshire.

Together these three days : All Hallows' Eve, All Saints and All Souls : are sometimes called Allhallowtide. The religious meaning faded for many, but the sense of the season as a time when the dead are near survived intact.

Folk customs that shaped the holiday

Between the Middle Ages and the 1800s, a rich layer of popular customs grew up around Allhallowtide in Britain and Ireland. Many of them are direct ancestors of what we do today:

• Souling. Poor people, often children, went from house to house offering prayers for the dead in exchange for soul cakes, small spiced breads. It is one of the clearest forerunners of trick-or-treating.
• Guising. In Scotland and Ireland young people disguised themselves and visited neighbors, performing a song, a poem or a joke in return for food, coins or nuts. The disguise was sometimes explained as a way to blend in with wandering spirits.
• Turnip lanterns. Hollowed-out turnips and mangel-wurzels, carved with grotesque faces and lit by an ember, lit the way home or warded off spirits. Their story continues in The Story of the Jack-o'-Lantern.
• Divination games. Apples, nuts and mirrors were used to forecast marriages and fortunes. Bobbing for apples and peeling an apple to see the initial of a future spouse both descend from these games.
• Mischief. The night had a long reputation for pranks, which were often blamed on fairies or spirits.

These customs were regional, informal and very local. There was no single "Halloween" : just a cluster of related traditions that shifted from village to village.

Crossing the Atlantic

The colonial American Puritans had little use for saints' days, and Halloween barely registered in early New England. It arrived in force with the waves of Irish and Scottish immigrants in the 19th century, especially after the Great Famine of the 1840s sent more than a million Irish across the Atlantic.

Immigrants brought guising, divination games and lantern-carving. In North America they found the native pumpkin, larger and far easier to carve than a turnip, and the jack-o'-lantern took on its modern shape. By the late 1800s magazines and party guides were promoting Halloween parties for young adults, full of fortune-telling games, apple bobbing and ghost stories.

Pranks, parades and the family holiday

In the early 20th century Halloween night had a rowdy side. Young men tipped outhouses, soaped windows and moved wagons onto rooftops, and in the 1920s and 1930s vandalism grew serious enough that towns looked for ways to channel it. The answer was organization: civic parades, school parties and community events. Anoka, Minnesota, began one of the earliest town-wide celebrations in 1920, explicitly to keep young people out of trouble.

Trick-or-treating as a household ritual spread in the 1930s, paused during wartime sugar rationing, and exploded in the baby-boom suburbs of the 1950s. Candy makers, costume companies and television all amplified it. You can follow that thread in Trick-or-Treating Explained, and see why the date itself never moved in Why Do We Celebrate Halloween on October 31?

Halloween today

Modern Halloween is overwhelmingly secular, enormously commercial and genuinely communal. The National Retail Federation's 2026 survey projected $13.5 billion in U.S. Halloween spending, with 74% of Americans planning to celebrate. Decorations ($4.3 billion) now rival candy ($4.1 billion), a sign of how much the holiday has moved from a single night of trick-or-treating to a month-long season of porches, pumpkin patches and haunted attractions.

The American version has also traveled back across the Atlantic. Ireland, the land of Samhain, now celebrates with pumpkins and costumes alongside barmbrack and bonfires; Derry hosts one of Europe's largest Halloween festivals. Read more in Halloween Around the World.

Timeline at a glance

Swipe or scroll sideways to see the whole table on a small screen.

Why it still resonates

Halloween has survived because each layer answers a real human need. Samhain marked the turning of the seasons. All Souls gave people permission to remember the dead. Guising and souling built neighborly exchange into the darkest time of the year. And the modern holiday lets children : and plenty of adults : play with fear in a safe, shared way.

The next time you carve a pumpkin or open the door to a small vampire, you're taking part in something that has been reinvented many times but never quite forgotten.

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