How Halloween Began?

In about the 5th century BC the Celtic people had a holiday called Samhain. This was the official end of summer. They believe that the spirits of the people that died that year would come back to search for living bodies on Samhain which was October 31st. They would dress in ghoulish costumes to frighten these spirits away. This later became called Halloween in honor of All Hallows Eve. Look here for more information: