Empress Euphemia’s rose from a freed slave to the most powerful woman in Rome in her time through her marriage to Justin I (450-527 CE). Historia Arcana (“Secret History”) by Procopius of Caesarea (c. 500 – c. 554) introduced the Empress Euphemia as Lupicina – a slave and a barbarian concubine of her owner.

This episode is also available as a blog post: http://martinifisher.com/2021/05/03/even-empresses-had-haters-tale-of-two-concubines-and-sensational-ancient-biographies/