Baghdad became a Buyid possession when Ahmad ibn Buya advanced from Ahvaz with his army and entered the city in December 945. Upon his arrival, he met with the Abbasid caliph al-Mustakfi, who agreed to give him control of the affairs of the state and conferred on him the honorific of "Mu'izz al-Dawla." News of this event was received negatively by the Hamdanid amir Nasir al-Dawla, who ruled over Mosul and the districts of the eastern Jazira. Nasir al-Dawla had previously controlled Baghdad in 942 and he still entertained hopes of regaining the city; Mu'izz al-Dawla's takeover of the capital was therefore an unwelcome development for him.
Nasir al-Dawla had reason to be confident that he could defeat Mu'izz al-Dawla if he made an attempt to capture Baghdad. His army had been bolstered by the arrival of numerous Turkish soldiers who had fled from Baghdad just before Mu'izz al-Dawla's entrance into the capital, and he was much more familiar with the territory between Mosul and Baghdad than his rival was. Mu'izz al-Dawla, on the other hand, was on less secure ground; Baghdad was in a sorry state thanks to years of mismanagement and he was hamstrung by its numerous financial and military problems. Nasir al-Dawla furthermore gained a pretext for war when in January 946 Mu'izz al-Dawla deposed and blinded the caliph al-Mustakfi and replaced him with the more obedient al-Muti'. As a result of these factors, Nasir al-Dawla took a belligerent tone with the Buyids; he withheld the payment of tribute to Baghdad, refused to recognize al-Muti' as caliph and continued to mint coins in al-Mustakfi's name.