It retells the events of the 1531 apparitions that led to the Marian veneration in Mexico City, New Spain.
It was drafted by the secular priest Miguel Sánchez and dedicated to Bishop Pedro de Barrientos Lomelin, based on the prophecy of the Woman of the Apocalypse in Revelation 12.
[1] The text stated for the first time that the image venerated by Mexicans was of miraculous origin and recorded that the dates of Guadalupana appearances were comprised between 9 and 13 December 1531.
In this way, the image of the Virgin of Guadalupe was established as true symbol of Mexican-ness.
[1] Because of this work, Francisco de la Maza called Miguel Sánchez one of the "four guadalupan evangelists".