Most scholars agree that Halloween as we know it originated some 2,000 years ago, when Celtic people in Europe celebrated the end of the harvest and the start of a new year in a festival called Samhain (pronounced “sow-win”). People also believed they could commune with the dead more easily during that time, lighting big bonfires to ward off spirits, according to The American Folklife Center.
The Celts also believed that the spiritual communication on Samhain made it easier for Celtic priests, or druids, to predict the future, according to History. To appease the deities, they built bonfires and sacrificed crops and animals. Villagers also attended the bonfire ceremonies wearing animal heads and skins as costumes.