The feast of Corpus Domini, today celebrated throughout the Christian world, wants to remember the Eucharistic miracle of Bolsena located on the north-eastern shore of the lake of the same name, which occurred in 1263. The most ancient chronicles tell us of a Bohemian priest, to whom tradition gives the name Peter of Prague, who in that time of theological controversies on the Eucharistic mystery was assailed by doubts about the real presence of Christ in the consecrated bread and wine.

To finally find peace, he resolved in his soul to undertake a long pilgrimage of penance and meditation towards Rome to pray at the tomb of St. Peter. After praying at the tomb of the prince of the apostles, refreshed in spirit he resumed his journey back to his homeland. Along the Via Cassia, he stopped to sleep in Bolsena near the Basilica of Santa Cristina and to thank God, the following morning, he asked to celebrate Holy Mass. During the celebration, after the consecration, in the hamlet of Ostia, a miracle appeared to his eyes which at first he did not want to believe.

That Host that he held in his hands had become flesh from which abundant blood miraculously dripped. Fearful and at the same time full of joy, he tried to hide what was happening from the few present: he concluded the celebration, wrapped everything in the white linen corporal used for the purification of the chalice which was immediately stained with blood and fled towards the sacristy. But during the journey some drops of blood fell on the floor, betraying the secrecy of the miracle.

Following this miracle, in 1264, with the Bull “Transiturus de hoc mundo”, Urban IV decreed that the feast of the Body of the Lord be celebrated every year throughout the Christian world and the beautiful and imposing Cathedral of Orvieto (TR), an Umbrian town a few kilometers from Bolsena, was built, where the reliquary containing the host is preserved inside.

The institution of the Corpus Domini procession has its origins in the ceremony with which the relics of the miracle, moved from Bolsena to Orvieto, were placed in S. Maria Prisca, in the presence of Pope Urban IV. In 1337 the government of Orvieto decided to annually carry the consecrated host and the Corporal in solemn procession through the streets of the city.
Bolsena began to solemnly celebrate the feast of Corpus Christi only a few centuries later after the blood-stained marbles, transported on a triumphal chariot built for the occasion, were transferred from the chapel of the Body of Christ to be kept in the new Chapel of the Miracle. The first solemn procession with the relics of the Miracle dates back to 1881.