Takeover of Azerbaijan
In 941 Marzuban and his brother Wahsudan ibn Muhammad, with the tacit approval of their mother, deposed and imprisoned their father Mahummad, whose harsh governance had alienated many of his subjects. Wahsudan replaced Muhammad as the ruler of Tarum. Muhammad, however, was approached by Abu'l-Qasim Ja'far b. 'Ali, the vizier of the ruler of Azerbaijan, Daisam. Ja'far, who had fled Azerbaijan, offered Marzuban the chance to overthrow his master and take over the administration of the province. Ja'far, Marzuban and Wahsudan were all Isma'ilis, perhaps explaining Ja'far's decision to turn to them. In any case, Marzuban agreed and invaded Azerbaijan. Daisam's Dailamite troops defected to the Sallarid and Marzuban was able to occupy Ardebil and Tabriz, while Daisam fled to the Ardzrunids of Vaspurakan.
Although Marzuban made Ja'far his vizier, the latter began to fear for his position. He went to Tabriz and invited Daisam to come there, then killed the Dailamite leaders of the city. Daisam returned and gained the allegiance of the Kurds, who were unhappy with Marzuban's administration. Marzuban and his Dailamites, however, defeated them and laid siege to Tabriz. He convinced Ja'far to leave Daisam's side; Ja'far was stripped of his position as vizier, although he was later reinstated.
Daisam and his followers, however, managed to escape from Tabriz before it fell and made their way to Ardebil. Marzuban, with aid from his brother Wahsudan, besieged the town. He bribed Daisam's vizier to convince him to surrender, which he did in 942 or 943. Daisam was allowed to take charge of Marzuban's castle in Tarum. The people of Arbedil, however, were punished for their treason; a heavy tribute was forced upon them and they had to dismantle the town wall.
After establishing his rule in Azerbaijan proper, Marzuban sought to expand his authority to the north and west. The Shirvanshah, for example, had to face an invasion of his territories by Marzuban's Dailamites; he defeated them but eventually agreed become Marzuban's vassal and pay tribute. By 945 he had also taken over Dvin. This policy of expansion was effective, for by the end of his reign Marzuban had gained the allegiance of most of the minor princes of the Caucasus and Armenia.