Khusro Parwez. During the time of the Holy Prophet of Islam, Yemen was under the suzerainty of Persia, and a Persian noble Badhan was the Governor. In 628 C.E. the Holy Prophet sent dispatches to the various contemporary rulers inviting them to embrace Islam. Among others the invitation was sent to Khusro Parwez as well, the 'Kisra' of Iran. When Khusro Parwez got the letter, he was infuriated. He tore the letter to pieces and instructed Badhan to send some agents to Madina to summon the Holy Prophet to his court.
Badhan complied with these orders, and sent some agents to Madina. These agents tried to prevail upon the Holy Prophet that it would be in his interest if he accompanied them to the court of the Kisra. The Holy Prophet suppressed his rage at the insolent message, and asked the agents of Badhan to see him the following day.
When the men from Yemen waited on the Holy Prophet the next day, he said: "The Kisra who had the audacity to summon me in his court has been summoned to the court of my Allah, and his abode is in hell. His son has murdered him. Go, tell your masters that the prophets of God do not attend the courts of temporal sovereigns and tell Badhan that his interest in this world as well as in the world hereafter lies in accepting Islam. If he accepts Islam, he can continue to be ruler of Yemen on behalf of the Muslims."
Badhan. When the message of the Holy Prophet was communicated to Badhan in Yemen that set him, thinking. These were no ordinary words, and obviously the man who had sent the message could not be an ordinary person. In the mean time news was received from Iran that Khusro Parwez had in fact been murdered and his son had ascended the throne. The new ruler of Iran also sent a command to Badhan not to interfere in any way with the affairs of the Arabian Prophet, and that the order of his father summoning the prophet of lslam to the court of Kisra was not to be enforced. At this turn of events, Badhan was much impressed. He became a Muslim, and many people of Yemen accepted Islam likewise. Yemen threw of its allegiance to Persia. Badhan continued to be the ruler of Yemen on behalf of the Muslims. The Holy Prophet appointed a Resident at the court of Yemen.
Aswad 'Ansi. A year later, Badhan died and was succeeded by his son Shahr. At this stage a false prophet rose in Yemen. He was one Aswad 'Ansi, an ugly man who kept his face veiled to hide his ugliness and was nicknamed, "The Veiled Prophet." By dubious methods, Aswad 'Ansi succeeded in winning a considerable number of followers. Within a short time, he became powerful enough to challenge Shahr who remained faithful to Islam. In the confrontation that followed, Shahr was defeated and killed, and Aswad Ansi captured power. Aswad 'Ansi now crowned himself as the king of Yemen, and repudiated allegiance to Madina. He forcefully married the beautiful widow of Shahr, Azad by name. Feroz a Minister under Shahr became a Minister under Aswad 'Ansi although he remained a Muslim. Qais bin Abu Yaghus, commander-in-chief of the forces of Shahr, became the commander-in-chief of the forces of Aswad 'Ansi. Aswad 'Ansi was a man of suspicious nature. He felt that in order to strengthen his position he must overthrow Feroz and Qais. Feroz and Qais soon fell out with Aswad 'Ansi. Azad bitterly hated Aswad 'Ansi. In conspiracy spearheaded by Qais, Feroz and Azad, Aswad 'Ansi was assassinated. Feroz who still professed Islam became the ruler of Yemen. He however, could not pull on with Qais for long. Feroz was of Persian descent while Qais belonged to the Arab tribe, of Bani Hamir. Qais made common with some other Arab tribes, and thought of capturing power. Feroz was no match for the combined strength of the Arab tribes. Lacking strength, Feroz fled to the hills. Thereupon Qais captured political power and became the ruler of Yemen.
Campaign in Yemen. On being ousted from power, Feroz who remained true to Islam sought help from Abu Bakr. Qais apostatized from Islam, and won the cooperation of all those who had previously supported Aswad'Ansi. Some tribes in Yemen, however, remained firm in their faith in Islam, and they rallied round Feroz. With the aid of these tribes, Feroz sallied down from the hills and advanced against Sana'a the capital of Yemen There was a confrontation in the plain outside Sana'a. In this confrontation, the forces of Qais were defeated, and he found safety in flight. Feroz once again became the ruler of Yemen. The restoration of Feroz did not bring peace to Yemen. Qais though defeated continued to be a source of trouble. He approached the Arab tribes and tried to win them to his cause in opposition to Feroz. Qais succeeded in winning Umr bin Maadi Kurb to his side. Umr was a poet and a firebrand fighter and his alliance with Qais made the position of Feroz difficult.
Feroz appealed to Abu Bakr for help. Abu Bakr ordered a two-pronged advance on Yemen. Muhajir b Umayya was directed to march from Makkah to Yemen. 'Ikramah bin Abu Jahal was directed to march from Mahrah to Yemen. 'Ikramah entered Yemen and camped at Abyan. Muhajir with his force advanced from Makkah and Taif. At the border of Yemen a tribe allied with Qais intercepted the advance of the force of Muhajir. The Muslims charged with great fury, and in the battle that ensued practically the whole of the tribe was exterminated. This victory of the Muslims unnerved the apostates. Instead of making common cause to give another battle to the Muslims, Qais and Umr fell out with each other. One day Umr surprised Qais and after taking him captive presented him before Muhajir, Umr had hoped that thereby he would win the favor of Muhajir. Muhajir, however, arrested Umr as well for his past misconduct. With the elimination of the two leaders, the apostate tribes had no will to fight. They laid down arms. and those who accepted Islam were granted amnesty, the rest were killed. That brought peace to Yemen. Qais and Umr were both sent in chains to Madina and there they were presented before Abu Bakr. At Madina, both Qais and Umr repented and were re-admitted to the fold of Islam.