The Corporal of Bolsena, Italy – 1264 A.D.
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 Aquinas’ composition, and by means of a Papal Bull instituted the feast of Corpus Christi.
Extraordinary Eucharistic Miracles that Left Physical Evidence
Catholics believe that Jesus Christ is really, truly, and substantially present in the Eucharist. There are many stories of Eucharistic miracles throughout Church history. These miracles are God's extraordinary interventions, meant to confirm faith in the real presence of the body and blood of the Lord in the Eucharist. The Lord performs these miracles to give us a sign, easy and visible to all, that in the Eucharist there is the true body and true blood of the Lord.
It’s important to note that no Catholic is required to believe any of these stories. Even if they have been investigated and approved by the Church, the Catholic dogma of transubstantiation does not depend on the authenticity of these stories (but it is based on Scripture and Tradition).
Miracle of Lanciano, Italy - 750 A.D.
In the 8th century, a priest in Lanciano Italy, was experiencing doubts about the real presence of Jesus in the Eucharist. In the middle of saying Mass, he said the words of Consecration (“This is my body,” “This is my blood”) and saw the bread and wine transform into real human flesh and blood. The blood coagulated into five globules (later believed to be representative of the five wounds of Christ). Word of the miracle quickly spread, the local Archbishop launched an investigation, and the Church approved the miracle.
The flesh is still preserved to this day. Professor of Anatomy Odoardo Linoli conducted a scientific analysis of the flesh in 1971 and concluded that the flesh was cardiac tissue, the blood appeared to be fresh blood (as opposed to blood that was 1200 years old), and there was no trace of preservatives.