Bolsena, 1264

In 1263, according to tradition, a Bohemian priest named Peter of Prague who doubted the Real Presence was celebrating Mass in Bolsena when the consecrated host is said to have begun to bleed, staining the corporal cloth on the altar. The stained corporal was brought to nearby Orvieto, where it is preserved in the Cathedral of Orvieto to this day.

The tradition holds that Pope Urban IV, moved by this event, instituted the feast of Corpus Christi. However, the feast of Corpus Christi did not begin solely because of this event; the liturgical celebration of the Eucharist had broader theological and pastoral roots, and the bull Transiturus was issued in 1264 in a wider context.

The corporal of Orvieto remains an object of veneration. The Church has not issued a formal decree declaring the Bolsena event supernatural. The account is preserved as a longstanding tradition associated with the shrine, and it is included in Saint Carlo Acutis's exhibition. Pilgrims can visit the Cathedral of Orvieto, where the corporal is displayed, and the chapel in Bolsena associated with the tradition.