What is the origin of Halloween — which ancient festival inspired it?

The origin of Halloween traces back to the ancient Celtic festival of Samhain (pronounced “Sow-in”). Celebrated around 2,000 years ago in Ireland and parts of Northern Europe, Samhain marked the end of the harvest season and the beginning of winter. The Celts believed that on the night of October 31st, the boundary between the living and the dead blurred, allowing spirits to roam the earth. People lit bonfires and wore costumes to ward off wandering souls — traditions that later evolved into Halloween customs.