Dhū Nuwās, (), real name "Yūsuf Asʾar Yathʾar" (Musnad: 𐩺𐩥𐩪𐩰 𐩱𐩪𐩱𐩧 𐩺𐩻𐩱𐩧, Yws¹f ʾs¹ʾr Yṯʾr), "Yosef Nu'as" (), or "Yūsuf ibn Sharhabīl" (), also known as "Masruq" in Syriac, and Dounaas () in Medieval Greek, was a Jewish king of Himyar between 517 and 525–527 AD, who came to renown on account of his persecutions of peoples of other religions, notably Christians, living in his kingdom. History Ibn Hisham's Prophetic biography (better known in English as the Life of Muhammad), describes the exploits of Yūsuf Dhū Nuwās. Ibn Hisham explains that Yūsuf was a convert Jew who grew out his sidelocks (nuwas), and who became known as "he of sidelocks." The historicity of Dhū Nuwās is affirmed by Philostorgius and by Procopius (in the latter's Persian War). Procopius writes that in 525, the armies of the Christian Kingdom of Axum in Ethiopia invaded Yemen at the request of the Byzantine Emperor, Justin I, to take control of the Jewish kingdom in Ḥimyar, then under the leadership of Yūsuf Dhū Nuwās, who rose to power in 522, probably after he assassinated Dhu Shanatir. Ibn Hisham explains the same sequence of events under the name of "Yūsuf Dhū Nuwās." Following this invasion the supremacy of the Jewish religion in the Kingdom of Ḥimyar, as well as in all of Yemen, came to an abrupt end. Imrū al-Qays, the famous Yemeni poet from the same period, in his poem entitled taqūl lī bint al-kinda lammā ‘azafat, laments the death of two great men of Yemen, one of them being Dhū Nuwās, whom he regards as the last of the Himyarite kings: One Syriac source appears to suggest that the mother of Dhū Nuwās may have been a Jew hailing from the Mesopotamian city of Nisibis. If so, this would place her origins within the Sassanid imperial sphere, and would illuminate possible political reasons for his later actions against the Christians of Arabia, who were natural allies of the Byzantine Empire. Many modern historians, with the exception of Christopher Haas, have argued that her son's conversion was a matter of tactical opportunism, since Judaism would have provided him with an ideological counterweight to the religion of his adversary, the Kingdom of Aksum, and also allowed him to curry favour with the Sassanid shahanshah. The Martyrs of Najran According to Ibn Ishaq, the king of Himyar named Dhu Nuwas had burned the Christians in Najran,