Baghdad. He could rely on many friendly military commanders to heed his call for assistance, and in the early months of the war several small regiments from Iraq, the Jazira, the Jibal, the Arab-Byzantine frontier and elsewhere arrived in Baghdad. Muhammad also had an ally in his nephew Muhammad b. Tahir, who was the governor of most of the eastern provinces, although at the time the latter was largely preoccupied with the rebellion of Hasan b. Zayd in Tabaristan. In order to augment the ranks of his soldiers, Muhammad instituted a draft in Baghdad and called on for volunteers to serve al-Musta'in. A group of Khorasani pilgrims en route to Mecca at the time the war began were asked to stay and fight. Many of the city's brigands were also recruited and provided with weapons. At first they were given mats to protect themselves and bags of rocks or bricks to attack the enemy with; later they were given clubs, placed under their own chief and registered in the military roll so that they could be paid. Arab Bedouins and Kurdish tribesmen from the surrounding regions also fought for al-Musta'in. In keeping with normal Abbasid court practice, gifts were routinely bestowed upon officers and soldiers by both al-Musta'in and Muhammad. Tabari's narrative of events contains numerous instances of commanders being rewarded for their service. They were given gifts on a number of occasions, such as their initial arrival in Baghdad with their troops, distinguishing themselves on the battlefield, or being selected to lead an important mission. Traditional robes of honor were regularly given out; other gifts included jewelry, ceremonial swords, money, and increased allotments for the troops. The exact size of the army under Muhammad's command is not explicitly stated, but it was likely much greater than al-Mu'tazz's forces. As many of his units were irregulars, however, their conduct in battle was not always reliable, and they were disciplined often for their failure to follow orders. In addition, while many army commanders were willing to pledge themselves to al-Musta'in's cause, not all of them were willing to take orders from Muhammad; there are multiple instances of pro-Musta'in regiments outside Baghdad acting independently and engaging the Turks on their own initiative. Al-Mu'tazz From the start of the crisis, al-Mu'tazz was concerned with portraying himself as the legitimate caliph. He had been proclaimed as heir-apparent during his father's lifetime, and according to