Guadalupe's image became a battle flag before it became a fixture of Sunday devotion, carried into Mexico's fight for independence by a priest who saw it as a symbol every side would recognise instantly.
A banner for independence
In 1810, the priest Miguel Hidalgo raised an image of Our Lady of Guadalupe as a rallying symbol at the start of Mexico's war of independence from Spain, deliberately invoking an image already understood as distinctly Mexican rather than purely Spanish colonial Catholic imagery, a choice that helped cement Guadalupe's identity as a national as much as a religious symbol going forward.
A basilica built because the old one was sinking
The original basilica built to house the image suffered serious structural subsidence due to Mexico City's soft lakebed soil, prompting construction of a new, modern basilica completed in 1976 specifically to protect and display the image safely, fitted with a moving walkway beneath the enshrined image to manage the very large volume of visitors without requiring them to linger directly in front of it.
As this entry's companion article covers
The documentary record, or lack of it, surrounding the original 1531 apparition account involving Juan Diego, and the later written sources describing the event, are addressed directly in this entry's companion article rather than repeated here.