On Oct. 31, families from across the world will celebrate Halloween, a traditional holiday of timeless age. But how did it actually begin?

I decided to do some research on the origins of Halloween and found intriguing results. As with many modern holidays, it is a variation on ancient religious observances. The earliest known form of Halloween is the Celtic holy day of Samhain.

Samhain began at sunset on Oct. 31 and continued until the sunset of Nov. 1, representing the end of the harvest and beginning of winter. Due to the surrounding decay of fall, occult magics were most powerful, and the veil between the dead and the living was at its thinnest, allowing for spirits to roam the earth. This led to the date being associated with supernatural figures, such as witches, ghosts and vampires.

As part of the campaign by the Catholic Church to undermine native religions, in the seventh century CE Pope Boniface IV (608–615) established All Saints’ Day, or All Hallows, on May 13 as a replacement for the Roman festival of Lemuria. However, people still celebrated Samhain, so to further discourage paganism, All Hallow’s Day was moved to Nov 1. The day before it was therefore All Hallow’s Eve, or Halloween.

As with the name and the date, Halloween traditions are also modern interpretations of ancient practices.

The name Jack-o’-lantern was first used to describe the ignis fatuus, a phenomenon that usually occurs over swamps and marshes where a floating ball of fire will dance through the air and disappear. The origin of the practice, however, is largely unknown and debated. Although it is popularly stated that it is an ancient Irish custom, no accounts earlier than the 18th century mention them.

Trick-or-treating lies in three main traditions. First, during Samhain, peasants and beggars would go from door to door and beg for food, sometimes to collect for a community feast. Second, in reverence of the dead, families would often leave outside offerings of sweetmeat and cake. Third, people would often disguise themselves by dressing up in fanciful costumes so that demons and spirits wouldn’t recognize them. Together, these practices formed the trick-or-treating that children across the globe participate in today.

Interestingly enough, ancient Halloween traditions have not yet disappeared. The Celtic tradition of lighting a bonfire has persisted. In ancient times, the bonfire served to protect people from the night- it served as a second sun, and from its flame the hearths of all homes were relit. People would jump through this fire to purify themselves, and sometimes animals were also led through it. Some communities still light a bonfire on Halloween, and the tradition of jumping through the fire survives in Guy Fawkes day.

Samhain itself has not died either. Wiccans still celebrate it as a spiritual holiday, reflecting on the dead and performing seances.