Yusuf Dhu Nuwas (also called Yusuf Asar Dhu Nuwas, Masruq, and Dunas Zhidovin) was the last king of Yemen (then called Himayar) from a Jewish dynasty of unknown origin.
He was the successor of Rabiah, from the same dynasty. He was reputed to have killed many Christians, and thus provoked a joint Ethiopian-Byzantine invasion in 525. He was defeated at the battle of Najran, and later committed suicide.
DhuNuwas marched against the latter city and, finding it impregnable, treacherously promised the inhabitants full amnesty in the case of their surrender.
DhuNuwas next sought their bishop, Paul, and when informed that he had been some time dead, he ordered his bones to be disinterred and burnt and their ashes scattered to the wind.
Dhu Nuwas's messengers arrived 20 January, 524, at Hufhuf (El-Hassa), near the Persian Gulf, where Al-Mundhir was then entertaining an embassy sent to him by the Emperor Justin and composed of Sergius, Bishop of Rosapha, the priest Abramos, and many other ecclesiastics and laymen, among whom was the Monophysite Simeon, Bishop of Beth-Arsam, in Persia.