Tahir ibn Muslim

Tahir ibn Muslim ibn Ubayd Allah was the first Husaynid emir, or sharif, of Medina.

He was the son of Abu Ja'far Muslim, a descendant in the ninth generation of Husayn ibn Ali. Abu Ja'far had migrated to Egypt from Medina, where the Husaynid line was prominent, and became an important figure at the court of the Ikhshidids and later the Fatimids.

Sometime shortly after his father's death in 976/7, Tahir returned to Medina, where he was quickly recognized by the rest of the Husaynids as their leader. He may have initially recognized the Abbasid caliph al-Ta'i, or the Fatimids may have engineered his rise. The Fatimid caliph al-Aziz Billah eventually sent an army to secure his allegiance.

He remained as ruler of Medina until he died in 992, being succeeded by his son al-Hasan ibn Tahir. Tahir's line was deposed and replaced by a collateral Husaynid line in 1007, led by Da'ud in al-Qasim.