Saint Privatus (?)

Fresco
Euphrasian Basilica, Poreč, Croatia

Several male Christian martyrs are said to have been beaten with cudgels.

The mountain redoubt seems to me to be the strongest evidence for this saint's identity, and given also the gray beard I would guess that this is St. Privatus.

The date of the fresco is also a problem. Most of the other frescos in the basilica are of a style that one would readily assign to the 5th or 6th centuries, but this one is decidedly medieval, and the torturers are dressed as if they were pages in a medieval court.

This image in full resolution

More of St. Privatus
More of St. Domnius
More of St. Timothy
More of St. Maurus of Parentium

Photographed at the basilica by Richard Stracke, shared under Attribution-NonCommercial-ShareAlike license.