What is Halloween? Meaning of the festival explained, why we celebrate it and how it was inspired by Samhain

Halloween is widely celebrated on 31 October every year, with festival now synonymous with horror movies, costume parties and pumpkins.

It has foundations in both the Christian observance of All Saints’ Day and Paganism, in the form of the Celtic festival of Samhain.

Here’s everything you need to know about Halloween, and how the key traditions around it developed.

Halloween is always celebrated on 31 October, which this year means it will be observed on a Monday.

It coincides with the eve of the Christian feast of All Saints’ (or All Hallows’) Day, with its name originating from “Hallows’ Eve”.

The word itself dates back to the 18th century, with the original meaning of “hallowed (or holy) evening”.

All Saints Day gives worshippers the opportunity to remember martyrs and saints, and originates as far back as the 4th century, although the date was not moved to 1 November until 837AD.

There has been much debate over Halloween’s origins – some believe that it is solely a Christian holiday, with others tracing its roots to Parentalia, the Roman festival of the dead.

However, the most commonly held theory is that its basis is found in Samhain, a Celtic festival marking the end of the harvest season and the onset of the cold darkness of winter.

It dates back as far as the 10th Century, having featured in Irish literature and folklore from the era, and is widely celebrated throughout Ireland, Scotland and the Isle of Man.

Samhain marked the beginning of the “darker half of the year”, between the fall equinox and the winter solstice, with festivities lasting for three days.

The day was brought about to honour the dead as they passed from the human realm into the spirit world, and was marked in a number of ways.

Historian Nicholas Rogers, author of Halloween: From Pagan Ritual to Party Night, told Time magazine that information on the details of the festival is limited, mainly coming from folkloric literature.

However, he added that “Samhain was a time of stock-taking and perhaps sacrifice — including probably animal sacrifice — during which pastoral communities [prepared] to survive the winter.”

According to popular folklore, at Samhain worshippers would dress in costumes made from animal hide, sharing food and alcohol as they swapped stories of the season.

It is believed druid priests would build huge sacred bonfires in which they used to offer sacrifices to the gods, after which participants took a flame back to their home to relight the hearth and protect their homes.

In the modern day, Samhain is still observed by Neo-Pagans and Wiccans who perform fire ceremonies and honour their dead.

With the coming of Christianity, Sanhain celebrations soon merged with All Saints’ and All Souls’ Day.

Many traditions associated with the festival were incorporated into the Christian calendar, and Irish immigrants carried their customs to America in the 19th century, which have now blended into Halloween.

While America has been credited with turning Halloween into predominantly secular, commercial enterprise, many of the customs we know today have deep-set roots.

Robert Burns’ poem “Halloween”, published in 1785, notes how “fearfu’ pranks ensue” and refers to the association of the night with “bogies” or ghosts.

In Scotland and Ireland it was traditional to grotesquely carve a turnip jack-o-lantern, although 19th-century American immigrants favoured the larger and softer pumpkin, which is much easier to carve.

Costumes have always been a key feature, dating back to Celts adorning themselves in animal skins during Samhain, and continued by Christians dressing as saints, angels and devils.

Like many of the modern holiday’s secular features, their prevalence snowballed in the US, where mass-produced costumes first appeared in the 1930s after Halloween parties surged in popularity.

Trick-or-treating has its origins in Christian practices such as mumming, souling and guising – which involved heading from door to door for donations of food or money.

The phrase “trick-or-treat” has been traced back to 1917 in Canada, with the practice again seemingly being popularised in the US during the 1930s