'Ali-yi Mu'ayyad enjoyed, by far, the longest reign out of all the Sarbadar rulers. The partnership with Darvish 'Aziz lasted for ten months; while 'Ali-yi Mu'ayyad, who was Shi'i, helped raised Shi'ism to the state religion, he opposed several of Darvish 'Aziz's theocratic ideas. Tensions were high when a campaign was begun against the Kartids of Herat. Even before they had met any resistance, the Sarbadar army erupted in violence. While on the march, 'Ali's men picked a quarrel with the dervishes; Darvish 'Aziz and many of his followers were killed trying to escape. 'Ali returned and attempted to destroy the power of the dervishes completely. He moved against their organization and forced them out of Sabzavar, and even destroyed the graves of Shaikh Khalifa and Hasan Juri. The dervishes, however, fled, being granted refuge by the Kartids, the Ja'un-i Qurban, and the Muzaffarids of Shiraz. Meanwhile, the Ja'un-i Qurban regained Tus, though the two sides seemed to have no further conflict. Amir Vali gained control of Simnan and Bistam, though Astarabad was temporarily reconquered by the Sarbadars (1365/6-1368/9. Administratively, 'Ali increased the quality of the coinage, and instituted tax reforms.