The Catholic Encyclopedia defines All Saints’ Day as a feast to “honour all the saints, known and unknown.” At the end of the second century, so-called Christians began to honor those who had been martyred for their faith and, believing that they were already with Christ in heaven, prayed to them to intercede on their behalf. A regular commemoration began when on May 13,b 609 or 610 C.E., Pope Boniface IV dedicated the Pantheon—the Roman temple of all the gods—to Mary and all the martyrs. Markale comments: “The Roman gods left their place to the saints of the triumphant religion.”

The change of date to November came under Pope Gregory III (731-741 C.E.), who dedicated a chapel in Rome to all the saints and ordered that they be honored on November 1. Exactly why he did this is unknown. But it may have been because such a holiday was already being celebrated on this date in England. The Encyclopedia of Religion points out: “Samhain remained a popular festival among the Celtic people throughout the christianization of Great Britain. The British church attempted to divert this interest in pagan customs by adding a Christian celebration to the calendar on the same date as Samhain. . . . The medieval British commemoration of All Saints’ Day may have prompted the universal celebration of this feast throughout the Christian church.”

Markale points out the increasing influence of Irish monks throughout Europe at this time. The New Catholic Encyclopedia also observes: “The Irish often assigned the first of the month to important feasts, and since November 1 was also the beginning of the Celtic winter, it would have been a likely date for a feast of all the saints.” Finally, in 835 C.E., Pope Gregory IV made this festival universal.

Unable to uproot pagan beliefs from the hearts of its flock, the church simply hid them behind a “Christian” mask. Highlighting this fact, The Encyclopedia of Religion says: “The Christian festival, the Feast of All Saints, commemorates the known and unknown saints of the Christian religion just as Samhain had acknowledged and paid tribute to the Celtic deities.”