The first of November has been instituted to honour all the saints, known and unknown, and, according to Urban IV, to supply any deficiencies in the faithful's celebration of saints' feasts during the year.

      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, neighbouring dioceses began to interchange feasts, to transfer relics, to divide them, and to join in a common feast; as is shown by the invitation of Saint Basil of Caesarea (397) to the bishops of the province of Pontus. 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. But the Church, feeling that every martyr should be venerated, appointed a common day for all.

      At first only martyrs and Saint John the Baptist were honoured by a special day. Other saints were added gradually, and increased in number when a regular process of canonization was established.

      Gregory III (731-741) consecrated a chapel in the Basilica of Saint Peter to all the saints and fixed the anniversary for Nov. 1. Gregory IV (827-844) extended the celebration on Nov. 1 to the entire Church. The vigil seems to have been held as early as the feast itself. The octave was added by Sixtus IV (1471-84).