St. Ambrose (340-397).  Born at Trier of a Roman family, he studied Law at Rome, entered public service and, while living in Milan, was unexpectedly chosen to be Bishop of that city by public acclamation (“Ambrose for bishop”).  He carried out the office assiduously, a true shepherd and teacher of the faithful, showing tremendous charity to all.  He guarded the rights of the Church and defended the faith against the Arian heresy.

Picture: Early mosaic of Ambrose that might be an actual portrait.