Alessandro Vitali
Madonna and Child with St. Cassian and an Angel

First quarter of the 17th century
Oil on canvas, 84.6 x 57.1 in. (215 x 145 cm.)
Originally in the Church of St. Cassian, Castecavallino di Urbino

This appears to be a modification of Virgin of the Pillar iconography, with the Madonna and Child in Heaven observing Jesus' sufferings at the pillar.

They are in turn observed by St. John Cassian on the left, with his crozier and a maquette that is a fair representation of the little Romanesque Church of St. Cassian in Castecavallino di Urbino. Cassian has a crozier because he founded a number of abbeys and was a major theoretician of the monastic movement in the 4th and 5th centuries. His image can be distinguished from those of St. Cassian of Verdun, who will have both a crozier and a mitre, and St. Cassian of Imola, a martyr who will have a palm branch in his hand.

John Cassian's feast is on July 23. He left a number of influential writings, but he has never been the subject of hagiography and gets not even a page in the 63-volume Acta Sanctorum.

In a witty detail on the right, the donor puts his hands together as if in prayer and engages the viewer's eye while an angel, perhaps his guardian, tries to divert his attention to what is above.

View this image in full resolution.
Also see this image of the Virgin of the Pillar.

Photographed in Urbino by Richard Stracke, shared under Attribution-NonCommercial-ShareAlike license.