The work, one of Magnasco’s masterpieces, represents a scene which is in many ways unusual. Inside a majestic building, the figure of Saint Carlo Borromeo, picked out by his red garments, appears surrounded by clergymen, a groom, angels, half-naked men and women with children. The clerics kneeling before the archbishop belong to the secular order of the Oblates, founded by Borromeo in 1578.
The painting, datable to the 1730s, belongs to the maturity of the artist. He renders the flickering figures with darting brushstrokes and touches of light falling only on certain parts of their bodies, which are otherwise almost monochrome.
The background is probably by Clemente Spera (Novara? c. 1661 - Milan 1742), who often collaborated with Magnasco, painting the architectural settings.