St. Pancras and Diocletian
Church of St. Pancras, Griesheim-sur-Souffel, France
This is one of the few images in which St. Pancras really does look like a 14-year-old. As in the Golden Legend, he stands before the Emperor and denounces the gods as "deceivers and seducers of their own sisters, who spare not even their parents."
Read more about St. Pancras.
Source: Ralph Hammann via Wikimedia Commons