After Mázyár’s death, Ḥasan b. Ḥusayn, the paternal uncle of 'Abdu`lláh b. Ṭáhir, was made governor of Ṭabar­ístán, and ruled it well and justly for three years, four months and ten days, and entrusted to Muḥammad b. Ibráhim the task of discovering Mázyár’s treasures. In Dhu`l-Ḥijja, A. H. 228 (= September, A. D. 843) Ḥasan b. Ḥusayn died, and was succeeded by Ṭáhir b. 'Abdu`llah b. Ṭáhir, who governed the country for one year and three months, until news came from Khurásán of the death of his father 'Abdu`lláh there, whereupon he went to Khurásán, leaving his brother Muḥammad b. 'Abdu`lláh to govern Ṭabaristán, which he did for seven years, assisted by 'Attáb b. Warqá ash-Shaybání. In Ṣafár, A. H. 237 (= August, A.D. 851) Muḥammad b. 'Abdu`lláh went to Baghdad, and Sulaymán b. 'Abdu`lláh became governor of Ṭabaristán. He governed with wisdom and discretion for three years, but in A. H. 240 (= A. D. 854—5) he made a secretary from Merv named Manṣúr b. Yaḥyá his minister, and this man intro­duced evil innovations and practised extortions, till he was dismissed by Ṭáhir b. 'Abdu`lláh, and Muḥammad b. Músá b. 'Abdu`r-Raḥmán (f. 105b) was made wazír in his place.