The Church celebrates the Solemnity of All Saints on November 1

The Solemnity of All Saints honors all known and unknown saints. Pope Urban IV instituted the feast to address instances where the faithful did not sufficiently celebrate individual saint feasts throughout the year.

In the early Church, Christians commemorated the death anniversaries of martyrs at the locations of their martyrdom. During the persecutions of Diocletian, the high number of martyrs made it impossible to assign a separate day to each individual. This led the Church to designate a common day for their veneration. Early mentions of a common day appear in a sermon from 373 and in a homily by Saint John Chrysostom in 407.

Initially, the liturgical calendar only assigned special days to martyrs and Saint John the Baptist. Other saints were added to the calendar gradually, and the number of celebrated figures increased following the establishment of a regular canonization process.