The trick-or-treat tradition probably dates back to the early English All Souls' Day parade, celebrated on the 2nd of November. During the festivities, the poor would beg for food and families would give them pastries called "soul cakes" in return for their promise to pray for the family's dead relatives.

The practice, which was referred to as "going a-souling", was eventually taken up by children who would visit the houses in their neighbourhood and be given ale, food, and money.

Dressing in costume for Halloween has both European and Celtic roots. On Halloween, when it was believed that spirits visited the earthly world, people were afraid of  encountering the spirits. They would wear masks when they left their homes after dark so that the ghosts would mistake them for fellow spirits.