The conspirators of Querétaro planned to begin their uprising in December 1810, according to México Desconocido. Their plan was discovered in September. When Miguel Hidalgo learned of it, he began the movement in Dolores, on September 16.
On the march, at the sanctuary of Atotonilco, Hidalgo took a banner of the Virgin of Guadalupe, according to INEHRM, the government’s institute for historical studies. A history booklet on the government portal gob.mx says that the movement gathered under this emblem, which “se dice” (it is said) came from the parish of Atotonilco.