Abdallah ibn Tahir al-Khurasani

Abdallah's early career consisted of serving with his father Tahir ibn Husayn in pacifying the lands of the Abbasid Caliphate following the civil war between al-Amin and al-Ma'mun.

Although Abdallah had been made the governor of Khurasan following his brother's death in 828, he only arrived in Nishapur in 830;[1] in the meantime he had been busy fighting more revolts.

Also in the east, in 834, an Alid, Muhammad ibn al-Qasim, revolted in Juzjan, but Abdallah's forces eventually managed to capture him.

Mazyar, however, was looking to expand his dominion and wanted to be free of Tahirid influence, so he refused to accept this and demanded that he be able to pay his tribute directly to the caliph.

Mazyar, a recent convert to Islam, heavily relied on the Zoroastrians of the province but in the end was captured, sent to Iraq and executed.