The founder of the Tahirid dynasty was Tahir ibn Husayn, a general who had played a major role in the civil war between the rival caliphs al-Amin and al-Ma'mun. He and his ancestors had previously been awarded minor governorships in eastern Khorasan for their service to the Abbasids. In 821, Tahir was made governor of Khorasan, but he died soon afterwards. The caliph then appointed Tahir's son, Talha, whose governorship lasted from 822–828. Tahir's other son, Abdullah, was instated as the wali of Egypt and the Arabian Peninsula, and when Talha died in 828 he was given the governorship of Khorasan. Abdullah is considered one of the greatest of the Tahirid rulers, as his reign witnessed a flourishing of agriculture in his native land of Khorasan, popularity in the eastern lands of the Abbasid caliphate and expanding influence due to his experience with the western parts of the caliphate.