Dhu Nuwas
Procopius, John of Ephesus, and other contemporary historians recount Kaleb's invasion of Yemen around 520, against the Himyarite king, Yusuf Asar Yathar, known as Dhu Nuwas, a Jew who was persecuting the Christian community of Najran. After much fighting, Kaleb's soldiers eventually routed Yusuf's forces and killed the king, allowing Kaleb to appoint Sumuafa' Ashawa', a native Christian (named Esimiphaios by Procopius), as his viceroy of Himyar.