Today is the traditional feast day of Pope St Gregory the Great.
Here, from contributors to the Medieval Religion discussion group, are a selection of images of him.
Gordon Plumb posted the following images in stained glass:
York Minster, NXI, 2b-4b (right-hand light)
Winchester, Hospital of St Cross & St Faith, South Transept, North-East Clerestory window:
Saint-Nicholas-de-Port, Bay 101, 6a-10a, (left-hand light):
Genevra Kornbluth added a page of sculpted and painted depictions of St Gregory, and dating from the 14th-16th centuries:
Jim Bugslag posted the manuscript illumination in the Très Riches Heures of Gregory's procession in Rome against the plague, when he saw the apparition of St Michael sheathing his sword atop Hadrian's Tomb, aka the Castel S. Angelo.
There are aselection of images of him from over the centuries illustrating the Wikipedia biography and article about him at Pope Gregory I
The nearest thing we possess as a contemporary likeness of St Gregory is one which depicts him, flanked by his parents, but which I cannot track down on the internet today.
A very popular dedpiction of him in the later middle ages was in the context of the story of the Mass of St Gregory, when there was vouchsafed a vision of Our Lord whilst St Gregory was celebrating Mass, so as to confound a member of the congregation who doubted Transubstantiation.