Many experts believe the druids were the first to observe Halloween. Dating back to 700 B.C., they celebrated the festival of Samhain (the end of the harvest and a time to honor the dead) on November 1. In the ensuing years, the night before became known as the Eve of All Hallows, a.k.a. Hallow Even, a.k.a. Hallow e'en.• Ever wonder how trick-or-treating got started? On the evening before Samhain, people left food on their doorsteps to keep hungry spirits from entering the house. Festivalgoers started dressing in ghost, witch, and goblin costumes so wandering spirits would leave them alone. To this day, these are Halloween's most popular costumes.• The word witch comes from the Saxon word wicca, which means "wise one."