Strolling along the central via Torino, one can easily encounter this church, one of the most interesting of the city, overlooking a small square. The elegant, yet understated, façade dates from the end of 1700s, while the interior - designed by architect Louis Cagnola - dates back to the early nineteenth century. The church contains some precious works. In the right aisle you can admire the cycle of paintings and frescoes in the Cappella della Passion, works by Bernardo Luini dating back to 1516. In the first chapel on the right is an altar piece by Gaudenzio Ferrari. The origins of this church can be traced back to 740. The building stands on the ancient ruins of the imperial palace built by Diocletian as the seat of the tetrarch that would have governed one of the four parts into which the Roman Empire was divided with Milan as the capital. During the XII century the church underwent a radical transformation considering its origins; the current features of interest are mainly attributed to the Baroque style façade.