Before he became a father of the Christian Church, Augustine of Hippo loved a woman whose name has been lost to history. This is her story.

She met Augustine in Carthage when she was seventeen. She was the poor daughter of a mosaic-layer; he was a promising student and heir to a fortune. His brilliance and passion intoxicated her, but his social class would be forever beyond her reach. She became his concubine, and by the time he was forced to leave her, she was thirty years old and the mother of his...