Ismá'íl the Sámánid, having entrusted the government of Ṭabaristán to his cousin Abu`l-'Abbás, set out for 'Iráq to seek for Muḥammad b. Hárún. On reaching Samnán, he received tidings of the death of the Caliph al-Mu'taḍid (A. H. 289 = A.D. 902). Muḥammad b. Hárún effected a junction with Justán [b.] Wah-súdán, and both swore allegiance to Sayyid Náṣir-i-Kabír. In A. H. 290 (A. D. 903) the latter resolved on subjugating Ṭabaristán. Abu`l-'Abbás summoned to his aid the Ispahbad Shahriyár, son of Pádhúsbán; the Ispahbad Sharwín, son of Rustam, king of the mountains; and the nephew of the latter, Parwíz, the lord of Láriján, and further wrote to Ismá'íl the Sámánid asking for help. In the month of Bahman, A. H. 299 (So A.;? 289) Muḥammad b. Hárún, Justán [b.] Wahsúdán, and Sayyid Náṣir reached Tamanjáda, and encamped in a plain known as Kázar. The war lasted forty days, and the people of ´Amul in fear sent their children and goods to the country villages. At length the army of Abu`l-'Abbás seemed to be defeated, and began to flee in rout to Mámṭír, but he, with Shahriyár (f. 124b) and Kawkabán of Daylam, hurled himself upon the centre of the army of Muḥammad b. Hárún, who, deeming the victory already won, had removed one foot from his stirrup and crossed it over his horse’s neck. His army, taken thus unawares, was routed, and fled to Anúshadádhán.

Ismá'íl the Sámánid had sent his son Aḥmad to help Abu`l-'Abbás, but he tarried on the way, hoping that his cousin might be defeated. Abu`l-'Abbás complained of this to Ismá'íl, who recalled Aḥmad to Bukhárá, and reproached him, saying, “Thou pretendest that if Ṭabaristán be lost, no harm will accrue to Bukhárá. Dost thou not know that, should such a thing happen, we should no longer be safe here?” Abu`l-'Abbás then went to Ray, and sent to Fáris, governor of Gurgán, bidding him be on his guard until Muḥammad b. Hárún’s death. Fáris forwarded this letter to Bukhárá, and requested Ismá'íl to send him his insignia, standard and ring. Muḥammad b. Hárún again collected an army and came to ´Amul. Fáris spread abroad a rumour that Ismá'íl was come, and on the day of battle stationed one of his officers dressed in Ismá'íl’s robes, wearing his insignia, and bearing his standard in the centre of the army. Then he came to Muḥammad b. Hárún with ten men, saying, “O man, art thou mad to come and draw the sword against thy master? Lo, he sends me with his army and his signet-ring, promising thee pardon and safety and the government of this province.” Muḥammad b. Hárún, seeing the signet-ring and other insignia, was confounded, and said to his men, “Do you remain where you are;” (f. 125a) then he said to Fáris, “Advance, let us go to the Master!” Thus Fáris brought him to the centre of his own army, where he at once cast him to the ground, put him in fet­ters, and carried him off prisoner. Of his army, some joined Fáris, others went to Baghdad, and the remainder stayed in Ṭabaristán. Muḥammad b. Hárún was carried to Bukhárá, paraded round the town, and then immured and starved to death. And so long as Ismá'íl the Sámánid lived, Abu`l-'Abbás ruled Ṭabaristán from Gurgán to Gílán.