Especially memorable, however, in the history of the Arabs is the conversion to Judaism of a powerful king of Yemen. The princes or kings of Yemen bore the name of Tobba, and at times ruled over the whole of Arabia; they traced their historical origin back to Himyar, their legendary origin to Kachtan. One of these kings, who went by the name of Abu-Kariba Assad-Tobban, was a man of judgment, knowledge, poetical endowments, and of valor which incited him to conquest. Abu-Kariba therefore undertook (about 500) an expedition against Persia and the Arabian provinces of the Byzantine empire. On his march he passed through Yathrib, the capital of northern Arabia, and not expecting treachery from the inhabitants of the town, left his son there as governor. Hardly, however, had he proceeded further, when he received the sad intelligence that the people of Yathrib had killed his son. Smitten with grief, he turned back in order to wreak bloody vengeance on the perfidious city, and after cutting down the palm trees, from which the inhabitants derived their principal sustenance, laid siege to it with his numerous band of warriors. A Jewish poet composed an elegy on the ruined palm trees, which the Arabs loved like living beings, and the destruction of which they bewailed like the death of dear relatives. The Jews rivaled the Chazraj Arabs in bravery in resisting Abu-Kariba's attack, and finally succeeded in tiring out his troops. During the siege, the Himyarite king was seized with a severe illness, and no fresh water could be discovered in the neighborhood to quench his burning thirst. Two Jewish teachers of the Law from Yathrib, Kaab and Assad by name, took advantage of Abu-Kariba's exhaustion to betake themselves to his tent, and persuade him to pardon the inhabitants of Yathrib and raise the siege. The Arabs have woven a tissue of legend about this interview, but it is certain that the Jewish sages found opportunity to discourse to Abu-Kariba of Judaism, and succeeded in inspiring him with a lively interest for it. The exhortations of Kaab and Assad raised his sympathy to so high a pitch that he determined to embrace the Jewish faith, and induced the Himyarite army to do likewise.