Italy · 13th Century
Rimini
In 1227, St. Anthony of Padua (who was actually from Lisbon, Portugal but is called "of Padua" because he died there) was preaching in the city of Rimini on the Adriatic coast of Italy. Rimini at that time had a significant population of Cathar heretics, a dualistic sect that rejected many Catholic doctrines including the Real Presence of Christ in the Eucharist. The Cathars believed that matter was evil and spirit was good, therefore they denied that God could truly be present in material bread and wine. St. Anthony, one of the Church's greatest preachers and theologians, had been sent to combat this heresy through his preaching.
About this miracle
Among the heretics in Rimini was a man named Bonovillo (also called Bonvillo), who was particularly vocal in his denial of the Eucharist. Bonovillo publicly challenged St. Anthony, proposing what he considered an impossible test that would prove the saint's teachings false. The most ancient biography of St. Anthony, called 'L'Assidua' (The Untiring), written shortly after his death, preserves Bonovillo's exact words: "I will believe in the Eucharist if my mule, after fasting for three days, adores the Host which you offer him rather than eating the fodder which I give him."
Bonovillo's challenge was based on the assumption that a hungry animal would naturally choose food over a piece of bread that - according to the heretic's belief - contained nothing special. He was confident that his mule would ignore the Host and eat the hay, thus disproving the Real Presence. St. Anthony, trusting completely in the truth of Catholic teaching and in God's power to manifest that truth, accepted the challenge.
On the chosen day and hour, St. Anthony and Bonovillo met in the Grand Piazza of Rimini (today called the Three Martyrs Piazza or Piazza Tre Martiri). A large crowd gathered - St. Anthony was followed by Catholic faithful who prayed for a miracle, while Bonovillo was accompanied by his fellow heretics who expected to see the saint humiliated. The tension was palpable. St. Anthony held between his hands the consecrated Host contained in a monstrance, the sun glinting off the golden vessel. Bonovillo held the reins of his mule, which had indeed been deprived of food for three full days and was visibly hungry. The heretic also carried fresh hay and grain - the most tempting food for the starving animal.
Bonovillo placed the fodder in front of the mule, expecting it to lunge for the food. But St. Anthony, with complete confidence in the Real Presence of Christ in the Host he was holding, spoke to the animal with the authority of a saint: "By the power of the Creator whom I hold in my hands, I command you, O beast, to come forward and render homage to your Lord, so that the wicked heretics may understand that every creature is subject to its Creator whom the priests hold in their hands on the altar."