The origins of Halloween come from the ancient Celts in Ireland, Scotland, Wales and Brittany. November 1 marked the beginning of a new year and the coming of winter. On October 31st they celebrated the Lord of the Dead with a festival called Samhain. During this festival, Celts believed the souls of the dead returned to mix with the living. In order to scare away any evil spirits, people would wear masks and light bonfires.
After the Romans conquered the Celts, their traditions were added to the Samhain festival, such as making apple and nut centerpieces for the Roman goddess of orchards, Pomona, bobbing for apples and drinking cider. In 835, Pope Gregory IV moved the celebration for martyrs (later all saints) from May 13 to November 1. The night before became known as All Hallow’s Even or “holy evening.” Over time the name was shortened to "Halloween". The Catholic Church celebrates All Souls Day on November 2.