 'Ali, led an army west towards Fars in an effort to wrest it from its ruler, the slave commander Sebük-eri.Since both al-Layth and another brother, al-Mu'addal, were participating in the campaign, Muhammad was left behind in the capital Zarang as al-Layth's representative.The campaign ended in disaster, with al-Layth being captured and sent to the Abbasid court at Baghdad; when news of this reached Zarang in early September, Muhammad was hailed as amir in the provinces still part of the amirate.