The rise of Helena is one of the more improbable careers of the late Roman world. Ancient testimony to her origins is unflattering and probably reliable: Ambrose calls her a stabularia, a stable-maid or innkeeper, and later sources place her birth in humble circumstances, traditionally at Drepanum in Bithynia (the town Constantine later renamed Helenopolis in her honour). She became the consort, whether wife or concubine is disputed, of the soldier Constantius Chlorus, and about 272-273 bore him a son, the future emperor Constantine.
When Constantius rose to the imperial college he set Helena aside for a politically advantageous marriage, and for a time she disappears from view. Her fortunes were restored spectacularly by her son. After Constantine became sole ruler, he brought his mother to court, conferred on her the exalted rank of Augusta, struck coins in her name, and gave her access to the imperial treasury and honours rarely granted to a woman.
The atlas records this well-attested imperial career as the secure historical core of Helena. She is a genuine figure of the fourth century, mother of the emperor who turned Rome toward Christianity, and a powerful patron in her own right, before ever the later legend of the relic-finder was attached to her name.