In 1263 a German priest, Peter of Prague, stopped at Bolsena while on a pilgrimage to Rome.
He was celebrating Mass in the Basilica of Bolsena, and when the moment of consecration arrived, the Host was transformed into Flesh.
This miracle strengthened the wavering belief of the priest in the Real Presence of Christ in the Eucharist.
The Sacred Body was inspected by Urban Pope IV and by St. Thomas Aquinas.
This miracle helped convince the Pope to extend the feast of Corpus Christi to the universal Church so that everyone could recognize the love God has for those who love and worship him.
The Eucharistic miracle of Bolsena, depicted by Raphael in a well-known fresco in the Vatican Palace, took place in 1263.
A German priest, Peter of Prague, stopped at Bolsena while on a pilgrimage to Rome.
He was pious, but he found it difficult to accept that Christ was actually present in the consecrated Host. While celebrating Holy Mass above the tomb of St.
Christina (located in the church named for this martyr), he spoke the words of consecration and immediately blood started to seep from the consecrated Host and trickle over his hands and onto the altar.
At first the priest tried to hide the Blood, but eventually he interrupted the Mass and asked to be taken to the neighboring city of Orvieto, where Pope Urban IV resided.
The Pope sent emissaries to investigate.
When the facts were ascertained, he ordered the bishop of the diocese to bring the Host and the linen cloth bearing the stains of Blood to him.
He had the relics placed in the cathedral. The linen bearing the spots of Blood is still reverently enshrined and exhibited in the Cathedral of Orvieto.
Pope Urban IV was prompted by this miracle to commission St.
Thomas Aquinas to compose the Office for the Mass and Liturgy of the Hours to celebrate the Most Holy Body of the Lord (Corpus Christi).
One year after the miracle, in August of 1264, Pope Urban IV introduced the Aquinas's composition, and by means of a papal bull instituted the feast of Corpus Christi.
When the facts were ascertained, he ordered the bishop of the diocese to bring the Host and the linen cloth bearing the stains of Blood to him.
Saint Gregory and Saint Bonaventure kneeling before the Miracle of Bolsena by Francesco Robbio. From the Collection of the Museum of the Diocese of Milan