The church of the Saints Fermo and Rustico, known as the Church of San Fermo Maggiore, was founded by Benedictine monks in the 11th century as a three-nave basilica with a large vaulted crypt on columns to house the relics of the patron saints (also known, incorrectly, as the lower church). With a transept based on two chapels rising from the apses, the layout is reminiscent of reformed monastic churches, such as Cluny Abbey. On the outside, the apse semicircles introduce a decorative system to Verona consisting of columns with Corinthian capitals in classical style.

In 1261, the church and Benedictine monastery became the property of the Franciscan friars who, in the early decades of the 14th century, during the time of Father Guardian Daniele Gusmari, renovated the building thanks to funding from the wealthy Guglielmo da Castelbarco, former podesta of Verona and lord of Vallagarina. The structure became a single nave, with a wooden ceiling shaped like an upturned ship's hull, decorated with portraits of 416 saints.

In the large triumphal arch of the main apse, a mural painting by the Master of the Redeemer depicts Friar Daniele kneeling and Castelbarco holding a model of the church (1316). The walls of the nave were also frescoed in the 14th century by other Giottesque painters, including Turone di Maxio.

The church later welcomed altars and statues: the pulpit by Judge Barnaba da Morano (1396); the Brenzoni tomb with the fresco of the Annunciation by Pisanello (1426); the tomb of the physician Girolamo della Torre by Andrea Riccio (1506) and the funeral monument of Dante Alighieri's heirs (1545).