Halloween, also known as All Hallows' Eve, can be traced back about 2,000 years to a pre-Christian Celtic festival held around November 1 called Samhain (pronounced "sah-ween"), which meant "summer's end" according to the Indo-European Etymological Dictionaries.
Since ancient records are sparse and sketchy, the exact nature of Samhain is not fully understood, but it was an annual meeting at the end of the harvest year, a time to gather resources for the winter and bring animals back from the meadows. The Celts believed that at this time of the year the souls of the dead were able to blend with the living because at Samhain the souls of those who had died during the year traveled into the otherworld.
Samhain is also believed to have been a time of communicating with the dead, according to Jack Santino, a Professor of Popular Culture at Bowling Green State University and a Director of the Bowling Green Center for Culture Studies.
The supernatural Samhain Celtic festival was pagan. It became the modern Halloween as an attempt to change Celtic practices and Christianize people. In 601 A.D. Pope Gregory the First issued the famous order to use native people customs and beliefs and consecrate it to Christ keeping the original schedule of worships. This brilliant basic approach was a continuous success. Samhain became Halloween. The Yuletide, mid-winter celebration, became our Christmas. Likewise, St. John's Day was set on Litha, the summer solstice. The Celtic underworld became identified with the Christian Hell.
Halloween presents a safe way to play with the concept of death. People dress up as the living dead, demons and witches, and fake gravestones adorn front lawns — activities that aren't tolerated at other times of the year.
But according to Nicholas Rogers, a history professor at York University in Toronto, "there is no hard evidence that Samhain was explicitly devoted to the dead or ancestor worship.
"According to the ancient legends, Samhain was the time when tribal peoples paid tribute to their conquerors and when the sidh might reveal the magnificent palaces of the gods of the underworld," wrote Rogers. Samhain was less about evil or death than about the changing of seasons and getting ready for the rebirth of nature as summer turned to winter.
Though a direct link between Halloween and Samhain has never been proven, many scholars believe that because All Saints' Day (All Hallows' Mass, celebrated on November 1) and Samhain, are so close together on the calendar that they affected each other and later combined into the celebration now called Halloween.