Augustinian friars arrived in Ixmiquilpan in 1548. The monastery was founded in 1550, and the buildings were completed in the early 1560s.
The Otomis had converted readily to Christianity, but their northern enemies the Chichimecas continued hostilites against the mission through 1569. In the 1960s, a remarkable set of 16th century murals painted by the local indigenous group (the Otomis) was discovered in the church nave, under layers of yellow paint. Frescoes depicted battles of Otomi warriors wearing pre-Conquest style battle garb (loin cloths, jaguar and coyote skins) and wielding traditional weapons (obisidian-edged clubs or macanas) versus mythological and fantastic creatures armed with bows and arrows (the preferred weapons of the Chichimecas). Thus, the fresco is: a cosmic battle between good and evil; a battle between European and Aztec religion; and a local battle between neighboring groups.
The background of acanthus leaves is inspired from Italian grotesque decorations, first introduced by Giulio Romano in his drawing for a casket (Italian Renaissance, 1530).
Why would the Augistinian friars allowed the Otomis to paint on the church walls such clearly non-Christian images with deep Aztec religous imagery? Perhaps the friars appropriated the dramatic indigenous scenes in order to help their converts understand the Christian struggle of good against evil. This mural is one document in the transition from early indigenous styles of representation that follow European examples.
The church facade has a cartouche depicting Augustinian tasseled hats.