In a monograph written in 1905 by historian Joseph Wils, professor of the Catholic University of Louvain, entitled Le Sacrement du Miracle de Louvain, are cited almost all the contemporary documents and testimonies. In Middleburg lived a noblewoman known by everybody for her great faith and devotion. The woman was also very attentive to the spiritual formation of her family and household staff. During the Lent of 1374, as she did every year in her house, she began to do penance in preparation for the coming of Easter. A few days before, a new manservant by the name of Jan was hired, who had not gone to confession for many years, in spite of the dissolute life he was living.
The woman invited all the household staff to go to Mass. Jan did not dare oppose this invitation so as not to disappoint her. He attended the whole Eucharistic celebration, and when it was time to receive Holy Communion, the man approached the altar with much superficiality.
As soon as he received the Host on his tongue, the Sacrament changed into bleeding Flesh. At once Jan took the Particle from his mouth; Blood dripped from the Sacred Flesh onto the cloth covering the altar rail. The priest realized at once what was happening, and with great emotion, carefully placed the miraculous Particle in a vessel inside the tabernacle. Jan repented and confessed his sin before everyone.
From that day on, he led an exemplary life and nourished a great devotion to the Most Blessed Sacrament to the end of his life. All the church and civil authorities of the city were informed of the miraculous event and after diligent investigation, the Archbishop authorized the cult of this miraculous event.