Germanus was born into a noble family in Gaul in the fourth century. He was well-educated as a child, then as a young man he went to Rome to study law. He practiced civil law in Rome and married a woman, Eustachia, from imperial circles.
The emperor appointed Germanus back to Gaul, where he served a duke entrusted with the Gallic provinces. Germanus resided in Auxerre. He hung his hunting trophies in a certain tree which had once been a site of pagan worship. The local bishop, Amator (who would later be canonized) was enraged, as the hanging of trophies in that way and in that spot resembled a pagan practice. He had the tree cut down and burnt Germanus’ trophies. Fearing the duke and Germanus’ response, he fled to Rome.
After seeking permission from the pope, Bishop Amator returned, tonsured Germanus against his will, and told him to live as one destined to be an ecclesiastical successor. That day he also ordained Germanus a deacon.