Halloween originated with an ancient Celtic festival called Samhain (pronounced Sah-ween or Sow-in). The Celtic New Year began on November 1. On the last day of the Celtic year, October 31, the Celts believed that ghosts roamed the world that night, causing harm to crops and creating mischief. So on October 31, the Celts dressed in scary costumes, parading around the village in the hopes of scaring away the mischievous spirits.

When Christianity arrived in Ireland, the church named November 1 as All Saints Day to honor saints and martyrs in an attempt replace or over shadow Samhain. Trick-or-treating originated from an All Souls Day tradition. People walked from village to village begging for “soul cakes.” In exchange for the “soul cakes,” a prayer would be said for the giver of the bread. The more bread they gave away the more people they had praying for their souls. In the 1500s, All Saint’s Day becomes All Hallows’ Day, and Samhain had become known as All Hallows’ Evening. Then eventually Hallow Evening became Halloween.