Arethas or Aretas, also known as Ḥārith ibn Kaʿb, was the leader of the Miaphysite Christian community of Najran in the early 6th century; he was executed during the persecution of Christians by the king of Yemen, Dhu Nuwas, in 523. News of this tragic story among the rest of the Christian persecutions quickly spread the surrounding areas until it reached the ears of Emperor Justin I of the Byzantine Empire and the Christian Kingdom of Aksum in Ethiopia, who sent in troops to depose Dhu Nuwas and end the persecution.