In 1531 a "Lady from Heaven" appeared to a poor Indian at Tepeyac, a hill northwest of Mexico City; she identified herself as the Mother of the True God, instructed him to have the bishop build a temple on the site and left an image of herself imprinted miraculously on his tilma, a poor quality cactus-cloth, which should have deteriorated in 20 years but shows no sign of decay 469 years later and still defies all scientific explanations of its origin.
It apparently even reflects in her eyes what was in front of her in 1531!

Her message of love and compassion, and her universal promise of help and protection to all mankind, as well as the story of the apparitions, are described in the "Nican Mopohua", a 16th century document written in the native Nahuatl language.
There is reason to believe that at Tepeyac Mary came in her glorified body, and her actual physical hands rearranged the roses in Juan Diego’s tilma, which makes this apparition very special.
An incredible list of miracles, cures and interventions are attributed to Her. Yearly, an estimated 10 million visit her Basilica, making her Mexico City home the most popular Marian shrine in the world, and the most visited Catholic church in the world next to the Vatican.
Altogether 24 popes have officially honored Our Lady of Guadalupe. His Holiness John Paul II visited her Sanctuary three times: on his first apostolic trip outside Rome as Pope in 1979, and again in 1990 and 1999.

The Feast of Our Lady of Guadalupe is celebrated on December 12th. In 1999, Pope John Paul II, in his homily from the Solemn Mass at the Basilica of Our Lady of Guadalupe, during his third visit to the sanctuary, declared the date of December the 12th as a Liturgical Holy Day for the whole continent.
During the same visit Pope John Paul II entrusted the cause of life to her loving protection, and placed under her motherly care the innocent lives of children, especially those who are in danger of not being born.