Today, Halloween is a day of tricks, treats, candy, pumpkin-carving, cider-drinking and costume-wearing, but the holiday has evolved immensely from Roman and Christian influences.

Originating with Samhain, the pagan Celtic celebration of the dead and the New Year, what we know as Halloween evolved as Julius Caesar and succeeding Roman leaders conquered Celtic lands in northern Europe and Britain in the first centuries B.C. and 43 A.D.

Having their own traditions, the Romans blended their beliefs with the Celts over the course of their 400-year rule. The Romans celebrated the festival of Feralia near the end of October, honoring the passing of the dead. They also observed a day in honor of Pomona, their goddess of fruit and trees.

The apple, the symbol of Pomona, was soon incorporated into the celebrations of Samhain, and early practices derived the tradition of “bobbing” for apples that is a staple of Halloween today.

Despite Christianity spreading throughout Celtic and Roman lands over hundreds of years after Roman rule, many continued to observe Samhain, to the dismay of the church. All Saints Day was introduced by Pope Boniface IV and commemorated on May 13 to honor dead saints and martyrs, but Pope Gregory IV moved the holiday to Nov. 1 in 835 A.D., in order to replace and co-opt the Samhain festival that was still being celebrated.

All Saints Day, as a church-sanctioned holiday of the dead, pleased the church, but people continued commemorating the holiday with the pagan traditions of Samhain, including lighting bonfires, holding parades and dressing up in costume.

All Saints day was known as All Hallows, or All Hallowmas, in Old English. As Samhain was celebrated on Oct. 31, the day before All Saints day, the day became known as All Hallows Eve. Later, the term was made into the contraction, Halloween.

Nov. 2 was instituted as All Souls Day in 1000 A.D., to honor the dead that were not saints. An All Souls Day tradition was to go “a-souling,” where the poor would ask for food door to door, in exchange for praying for the souls of dead relatives to go to heaven. The church preferred this practice to those of the pagans. The poor were given “soul cakes” for their prayers, or sometimes for a song and dance. Children would also often perform for food, ale, or money.

However, people soon began celebrating the saintly and non-saintly dead on Nov. 1, Hallowmas/All Saints Day.

Learn more about Halloween: Pagan Beginnings, From Europe to America.