On the morning of December 9th, 1531, Juan Diego was walking near the hill of Tepeyac when seemingly from nowhere began to hear music. Suddenly, in front of him, a radiant cloud appeared and a woman dressed much like an Aztec princess spoke to Juan in his native Nahuatl language identified herself as the Virgin Mary, "Mother of the very true deity". She asked Juan to have a church built at that site in her honor.
Juan Diego went straight down the hill and located the bishop Juan de Zumarraga. After he relayed the vision and Mary's request for a church built on the hill, the bishop informed him that he would need a sign from Mary for the church to be built. He asked Juan to return to Tepeyac Hill and ask the lady for a miracle to prove the story he relayed.
In the very early years of December 12th, Juan's uncle became extremely sick and so he set out to Tlatlolco to bring a priest so that his uncle could give his final confession. On the path, the Virgin Mary appeared again and said
"¿No estoy yo aquí que soy tu madre?" ("Am I not here, I who am your mother?")
She explained to Juan that his uncle was now healthy and that he should gather flowers from the top of Tepeyac Hill (there should have been no flowers as it was generally barren during the winter months). At the top of the hill, to his amazement he found Castilian roses in bloom. Not only are Castilian roses not native to Mexico, they would not be in bloom during December if they had been planted. He quickly gathered the roses in his tilma and returned to the archbishop of Zumaaraga. When he opened his tilma to show the bishop his flowers, the fabric of the tilma had been stained to show the image of the Virgin, exactly as he had described her from his visions.
On December 26th, 1531, the tilma was processed through the town to the hill of Tepeyac where a small, quickly built chapel had been built where Mary requested it. The first recorded miracle of the chapel then happened - during displays of martial presence to honor Mary, an arrow was accidentally loosed and it lodged into the neck of one of the townspeople. Quickly he was carried to the image on the tilma and the townspeople prayed begging for the Virgin to intercede. Miraculously, the arrow was removed and the person had no wound.
In 2002, Juan was canonized as Saint Juan Diego Cuauhtlatoatzin. The tilma is stored on display at the Basilica of Our Lady of Guadalupe (Basílica de Nuestra Señora de Guadalupe) , hanging above the altar.