The church of San Maurizio al Monastero Maggiore stands on the site of a former place of worship, conceivably from the Lombard period, and is adjoined to the convent of the Benedictine nuns, the largest and oldest female monastery in Milano. Today, parts of the monastic complex that were located on the ruins of the Roman circus and walls still remain, alongside the church of San Maurizio and portions of the cloisters which are integral parts of the adjacent Civic Archaeological Museum.
The construction works on the edifice that we see today began in 1503 and are possibly attributable to Gian Giacomo Dolcebuono, assisted by Battaggio and Amadeo. Fifteen years later, Cristoforo Solari completed the building. The main patrons were the Bentivoglio family who, together with the Sforza family - with whom they was related by marriage - were linked to the Benedictine nuns Monastero Maggiore. Not by chance it was Alessandro Bentivoglio, his wife Ippolita Sforza and his daughter Alessandra, the future abbess, who allocated a substantial sum of money for the church embellishments.
The church has an elongated rectangular nave that, still today, is divided by a partition into two sections. The front destined to the congregation, the back to the nuns' choir. In the second half of the sixteenth century, Carlo Borromeo decided to moderate the partition grille between the cloistered area and the congregation to further isolate the cloistered nuns.
It can be said that the church has a dual identity. A plain and austere façade in gray Ornavasso stone contrasts with a sumptuous interior that houses cycles of paintings by some of the major sixteenth-century Lombard artists: Bernardino Luini and his sons, Paolo Lomazzo, Ottavio Semino, Callisto Piazza and Simone Peterzano.
The church of San Maurizio al Monastero Maggiore contains an extraordinary number of masterpieces.
In particular, the frescoes of the partition, all by Bernardino Luini, representing saints, martyrs, and cherubs inserted in illusionistic false architecture, plus, the renowned Adorazione dei Magi (Adoration of the Magi) by Antonio Campi above the main altar and the early sixteenth-century wooden choir, attributed to Gian Giacomo Dolcebuono, in the centre of nuns’ section.
A massive and valuable pipe organ by Gian Giacomo Antegnati, with shutters painted in tempera by Francesco Medici, stands in the monks' choir of the church.
Presumably the two frescos with portraits of elegant donors kneeling and presented by saints, depicted in the lunettes of the partition, represent the patrons Alessandro Bentivoglio and Ippolita Sforza.
The Besozzi chapel, the third on the right, depicts scenes of the martyrdom of S. Caterina d’Alessandria. According to Matteo Bandello, a novelist of the era, the saint's face in the beheading scene represents the Contessa di Challant who, accused of being the instigator of her lover’s killing, was executed in 1526 at the Castello Sforzesco.