For more than a century the majority of the caliph's mercenaries had consisted of Turks, but with the Biiyid conquest Dailamites began to usurp their privileges. The Turks, however, resisted them. Indeed Mu'izz al-Daula's chief commander, Sebiik-Tegin, was himself a Turk. A further reason for the antagonism was religion. The DailamI were Shl'l, the Turks Sunni. Mu'izz al-Daula at first alienated the Turks, but then succeeded in working out a policy of compromise, his concern for the continuation of which is clearly discernible in the political testament which he left his son and successor 'Izz al-Daula and which is recorded by Miskawaih. He specifically recommended that Sebiik-Tegin be retained in office and insisted that Turkish claims should receive fair consideration. Two other urgent problems were also dealt with in this testament. One concerned Buyid policy towards the Hamdanids, the other advocated the recognition of Rukn al-Daula's supremacy. The young prince was also enjoined to respect and honour his elder cousin, 'Adud al-Daula.
At first 'Izz al-Daula followed his father's advice. He continued the campaign against the Shahinids in the marshlands, which had come to a halt with his father's death, but victory eluded him. He ignored what was happening on the Byzantine frontier, declaring this to be a matter for the caliph. Indeed when in 971 the Byzantine army penetrated deep into northern Mesopotamia, he did not even return to Baghdad. The volunteer force assembled to defend the faith now became the nucleus of a personal army in the hands of Sebiik-Tegin, who felt himself slighted by 'Izz al-Daula and increasingly driven to oppose him. In 973 'Izz al-Daula, against the advice left by his father, undertook an expedition against Mosul in order to avert an impending financial crisis. The result was a complete fiasco - the Hamdanids marched on Baghdad and it appears that Sebiik-Tegin was in secret collusion with them, hoping thereby to overthrow the Buyids in Iraq. cIzz al-Daula now resolved to confiscate the Turkish fiefs in order to overcome his financial straits, and with this end in view advanced on Khuzistan, where most of these fiefs were situated, at the same time declaring Sebiik-Tegin dismissed. The latter rallied the forces loyal to himself while 'Izz al-Daula moved to Wasit and there entrenched himself. He scornfully rejected Sebiik-Tegin's offer to relinquish Baghdad while retaining southern Iraq, whereupon the rebellious Turk marched on Wasit and laid siege to it. 'Izz al-Daula's fate might well have been sealed had not reinforcements come to his aid from the eastern territories of the empire.
The campaign to relieve Wasit was entrusted to 'Adud al-Daula. For nearly twenty years he had ruled in peace. He had helped Mu'izz al-Daula capture 'Uman and then promptly had marched on Kirman, which had once again become the scene of internal conflicts between the Banu Ilyas. The province was now for the first time directly annexed by the Buyids and Abu'l-Fawaris (Sharaf al-Daula), the seven-year-old son of 'Adud al-Daula, was nominally appointed viceroy. These new conquests to the south and east had made Fars doubly secure, and 'Adud al-Daula could now concentrate his undivided attention on the west. His father's decision to entrust him with the relief of 'Izz al-Daula could scarcely have been more propitious. Since his cousin's accession, he had been viewing the situation in Iraq with growing concern, for as future senior amir he had more than a casual interest in preserving and strengthening Buyid rule there. He was certainly already contemplating the removal of the Baghdad line because of its proven inability to govern, and this brought him into conflict with his father, who wished to uphold the Iraq branch of the family at all costs. 'Izz al-Daula had faithfully carried out his father's policy in this respect and had unquestioningly recognized Rukn al-Daula's senior amirate, but his attitude towards 'Adud al-Daula was more complex.
The roots of his ambivalent attitude lay in the problem of the rights of succession to the title, discussed above. 'Adud al-Daula had granted asylum to a brother of 'Izz al-Daula who had instigated a rebellion in Basra and had been driven to flight. 'Izz al-Daula responded by obstructing the activities of 'Adud al-Daula's agents who were in Baghdad to purchase various requirements for his army and court. 'Adud al-Daula thereupon seized the opportunity afforded by Mu'izz al-Daula's death of occupying 'Uman and incorporating it in Fars. These relatively trifling signs of enmity suddenly assumed a new complexion when 'Izz al-Daula ran into serious difficulties and found himself entirely dependent on help from the east. 'Adud al-Daula did indeed comply with his father's order to march on Wasit but he protracted his journey in the hope that his cousin would in the meantime be overpowered, thus leaving the way open for him. But 'Izz al-Daula held out, and 'Adud al-Daula found himself reluctantly obliged to reinstate him in Baghdad.
There an army mutiny gave 'Adud al-Daula the opportunity for which he had been longing. He deposed his hated and despised cousin and assumed power himself. But this action brought him the strong disapproval of his father, who, invoking a pledge given to Mu'izz al-Daula, categorically forbade the exclusion of the Baghdad line. An offer by his son to pay him tribute for the possession of Iraq was promptly rejected. After numerous exchanges between Baghdad and Ray 'Adud al-Daula was constrained to return to Shiraz empty-handed. The sole achievements of his intervention in Iraq were the overthrow of Sebiik-Tegin's uprising (the latter had died during the siege of Wasit) and the provisional retention of his supremacy in Iraq by naming 'Izz al-Daula as his viceroy and leaving one of his own most trusted officers in Baghdad as commander-in-chief of the army. 'Izz al-Daula, however, was so certain of support in Ray that he immediately reverted to the status quo after 'Adud al-Daula's departure. He was equally confident that the other powers in Mesopotamia were behind him. Indeed both the Hamdanids and the Shahlnids in the marshlands realized that they fared better when there was a weak Buyid in Baghdad. 'Adud al-Daula had demonstrated by his admittedly few but successful undertakings that he was a ruler who had to be taken seriously.