Mas'ud's first three successors ruled for a period totaling only three years. Both of the first two men had served as his military commanders; Mas'ud's brother Shams al-Din came next, only to fall as well. These internal conflicts were countered by good news on the external front; namely, the death of Arghun Shah in 1343, and the rise of his successor Muhammad Beg, who abandoned the alliance of the Ja'un-i Qurban with Togha Temur in favor of one with the Sarbadars. Shams al-Din was replaced in turn by the dervish Shams al-Din 'Ali in 1347, marking the loss of power by Mas'ud's adherents. Shams al-Din 'Ali was an effective administrator, reorganizing the state finances, carrying out tax reforms, and paying officials in cash. As a religious man, he attempted to stamp out prostitution, drugs and alcohol, and lived a simple life. His military was effective; although he failed to take Tus, he was able to destroy a rebellion in Damghan in the west. He was, however, prevented from turning the Sarbadar state to the Shi'i creed by Mas'ud's supporters, who kept the government Sunni. In the meantime, he gained enemies among the opponents of the dervishes, as well as the corrupt officials of the state that hated his reforms. One of these officials named Haidar Qassab, who was possibly a member of the artisan guild, murdered him around 1352.