Halloween has its origins in the ancient Celtic celebration called Samhain (pronounced sow-in). The Celtic people lived in Ireland, the United Kingdom, and northern France over 2.000 years ago. The Celtic New Year began on November 1. Samhain was a festivity that celebrated the end of summer and the harvest season on the day before the new year. During this festival, the Celts would wear costumes and try to tell each other their future.
By the time Christianity had spread to the region in the ninth century A.D., Nov. 1st had been designated All Saints Day or All-hallows. The day before, October 31st, was referred to as All-hallows. The day before, October 31st, was referred to as All-hallows Eve. It is now simply called Halloween.