The most famous and beloved icon in all Mexico, the Virgin of Guadalupe is the patron saint of the country and the “Empress of Latin America.”
To Mexicans, she is The Mother. You will never enter a Catholic church in Mexico without finding her portrait somewhere.
This is her story: In 1531, an indigenous man, Juan Diego, was on his way to church when the Virgin appeared to him on Tepayac Hill, near Mexico City.
She instructed him to tell the bishop to build her a church on that spot. But poor Juan Diego, being only an Indian, could not convince the bishop he was telling the truth.
So the Virgin appeared to him again. At her feet, Spanish roses grew, even though it was winter. She told him to wrap them in his cloak and take them to the bishop as proof of the miracle.
When Juan Diego spilled the roses at the bishop’s feet, the brown-skinned Virgin’s image had been imprinted on the cloak—which is now in the Basilica of the Virgin of Guadalupe that stands on Tepeyac Hill.
In San Miguel de Allende, a large banner image of the Virgin is mounted over the gate in front of the Parroquia. Late on the evening of the 11th, the mariachis gather before the image. At the stroke of midnight, they serenade her with “Las Mañanitas” the Mexican Happy Birthday song.
A highlight of the day is a children’s procession. It usually begins with a float featuring a young woman dressed as the famous icon of the virgin and a boy as Juan Diego at her feet. Other children in the procession will dress up as campesinos, perhaps with a mustache drawn on and a poncho festuring the image of the virgin. The procession ends at the Jardin.
Though the holiday is December 12th, the procession may be a day or two earlier.
San Miguel de Allende features decorated altars all over town.
The Day of Guadalupe is the first of the December events in San Miguel de Allende, and it unofficially inaugurates the Christmas season in town.
Source: http://www.experience-san-miguel-de-allende.com/