Every year on 31 October, millions of vampires, werewolves and witches knock on doors and carve faces into pumpkins. The customs feel ancient, and some of them are, but Halloween as we know it grew from several roots: a Gaelic harvest festival, the Christian feasts of the dead, the lanterns of Irish and Scottish villages, and a 20th-century North American invention. Here is how they came together.

The name: All Hallows' Eve

Halloween is the evening before All Hallows' Day, or All Saints' Day, on 1 November. The word comes from the Lowland Scots form of All Hallows' Eve, in which even, the Scots word for evening, was shortened to e'en. So Halloween simply means the eve of the saints.

Samhain, the end of the harvest

In Ireland, Scotland and the Isle of Man, Samhain was one of the quarter days of the medieval Gaelic calendar, celebrated from 31 October to 1 November. It marked the end of the harvest and the beginning of the dark half of the year. Many people believe Halloween grew out of Samhain, and some of its customs may have. Other historians argue that Halloween began independently as a Christian holiday, the vigil of All Saints' Day. The honest answer is that both traditions fed into it.

All Saints and All Souls

The Christian side has its own long history. In the 730s Pope Gregory III dedicated an oratory in Old St Peter's in Rome to all the saints. By around 800, churches in Ireland and Northumbria were keeping an all-saints feast on 1 November, and in 835 Emperor Louis the Pious made it a holy day across the Frankish Empire, at the request of Pope Gregory IV. The next day, 2 November, became All Souls' Day, for praying for the dead, a date standardised by Odilo, the abbot of Cluny. In the late Middle Ages the poor, often children, went from door to door collecting soul cakes in return for prayers for the dead, a custom called souling that dates back at least to the 15th century and may be one ancestor of trick-or-treating.

Guising and false faces

In Scotland and Ireland, people went guising: dressing up in disguise and visiting houses for food or coins. Mumming and guising are recorded from at least the 16th century, and guising at Halloween was widespread by the late 19th century. The masks were called false faces, a term recorded in Ayr in Scotland in 1890.

Turnips before pumpkins

Before pumpkins there were turnips. In the 1800s, people in parts of Ireland, Scotland, Wales and England carved hollowed-out turnips or mangel-wurzels into lanterns, often with grotesque faces. An Irish folk tale from the 1700s explains them: Stingy Jack, a lazy and cunning blacksmith, tricked the devil and was barred from both heaven and hell after his death, so he wanders the night lighting his way with a burning coal in a hollowed turnip. The name jack-o'-lantern is older still. It first meant a night watchman or the ghostly light over marshes known as a will-o'-the-wisp.

Irish and Scottish immigrants carried Halloween to North America in the 19th century, where the larger, softer pumpkin was easier to carve. American pumpkin carving is recorded by 1837, and a newspaper in Kingston, Ontario, linked carved pumpkins to Halloween in 1866.

Trick or treat

The phrase is younger than most people think. It first appears in print in 1917, in Ontario, Canada. The custom spread through the northern and western United States in the 1930s and across the rest of the country in the 1940s and early 1950s, held back for a few years by sugar rationing during the Second World War. By 1952, when Disney released a cartoon called Trick or Treat, it was firmly part of American popular culture.

Halloween in Slovakia

In Slovakia and the Czech Republic the same days are quieter. Around 1 and 2 November, at Dušičky, the little souls, families visit cemeteries and light candles on the graves, and on a clear evening whole hillsides glow. Halloween costumes and carved pumpkins have arrived too, but the old way of keeping the night of the dead is still the candle on the grave.

Why vampires, werewolves and witches?

Halloween costumes began as disguises, and the night creatures of folklore were the obvious choice: the dead who would not stay in their graves, the neighbours who ran with the wolves, and the witches who flew on the darkest nights. Their real stories are in Vampire Folklore, Werewolf Legends and Types of Witches.

Planning a Halloween party? Turn it into a creature quiz party where every guest finds their creature and gets a diploma, or start with the free Which Creature Are You quiz.