All Saint's Day is a Christian holy day observed by many Western churches on November 1 and by Eastern churches on the first Sunday after Pentecost. The day now honors all saints of the church, even those not known by name. All Saint's Day is celebrated by Roman Catholics, the Orthodox, Anglicans, and Lutherans. However, because of their differing understandings of the identity and function of the saints, what these churches do on the Feast of All Saints differs widely. For Roman Catholics, the Orthodox, and to some extent, Anglicans, All Saints is a day to remember, thank God for, but also to venerate and pray to the saints in heaven for various helps. For Lutherans the day is observed by remembering and thanking God for all saints, both dead and living. It is a day to glorify Jesus Christ, who by his holy life and death has made the saints holy through Baptism and faith.
In the sixth century, Pope Boniface IV accepted the Pantheon as a gift from the Emperor Phocas and proclaimed May 13, 610 Feast of All Holy Martyrs held. He dedicated it as the Church of Santa Maria Rotonda in honor of the Blessed Virgin and all martyrs.
During Pope Gregory III's reign, the festival was expanded to include all saints and a chapel in St. Peter's church was dedicated accordingly. In 835, Pope Gregory IV changed the date to November 1 and the name to Feast of All Saints.
In the early days the Christians were accustomed to solemnize the anniversary of a martyr's death for Christ at the place of martyrdom. In the fourth century, neighboring dioceses began to interchange feasts, to transfer relics, to divide them, and to join in a common feast. Frequently groups of martyrs suffered on the same day, which naturally led to a joint commemoration. In the persecution of Diocletian the number of martyrs became so great that a separate day could not be assigned to each. The Church, feeling that every martyr should be venerated, appointed a common day for all.
The first trace of this is found in Antioch on the Sunday after Pentecost. There is also mention of a common day in a sermon of Saint Ephrem the Syrian, and in the 74th homily of Saint John Chrysostom of Constantinople.
At first only martyrs and Saint John the Baptist were honored by a special day. Other saints were added gradually, and increased in number when a regular process of canonization was established. As early as 411 there is in the Chaldean Calendar a Commemoratio confessorum for the Friday after Easter.
