Halloween began as the festival of Samhain. It was part of the ancient Celtic religion in Britain and other parts of Europe. At the end of summer, the Celts thought the barrier between our world and the world of ghosts and spirits got really thin.
Straddling the line between fall and winter, plenty and paucity, life and death. Halloween is a time of celebration and superstition. It is thought to have originated with the ancient Celtic festival of Samhain, when people would light bonfires and wear costumes to ward off roaming ghosts.