[1] During the Arab invasion of Iran, the Sasanian king Yazdegerd III (r. 632–651) sent 1,000 cavalrymen under Siyah al-Uswari to defend Khuzestan.
[1][2] However, the story about them converting to Islam is most likely inaccurate, since 15 years later, some members still appear with Zoroastrian names, such as a certain Mah-Afridhan.
[1] During the Second Fitna, the Asawira under Mah-Afridhun helped the Tamim tribe in the rebellion that killed the governor of Basra, Mas'ud ibn Amr (d. 684).
However, this made the Arab statesman al-Hajjaj ibn Yusuf disband the Asawira, by destroying their homes, reducing their salary, and resettling them to other cities.
[1] Some of their descendants are later mentioned in some sources, such as Musa ibn Sayyar al-Uswari,[4] who was the student of Hasan of Basra, a prominent Muslim scholar, who was also of Iranian origin.