Caliphal Civil War ( 865 – 866 ) The Caliphal Civil War of 865 - 866 was an armed conflict during the " Anarchy at Samarra " between the rival caliphs al - Musta ' in and al - Mu ' tazz , fought to determine who would gain control over the Abbasid caliphate . The war , which lasted for about a year , largely revolved around a prolonged siege of Baghdad and ended with al - Mu ' tazz as sole caliph . Al - Musta ' in was abandoned by his supporters and forced to abdicate ; in spite of a guarantee that his life would be spared , he was executed shortly afterward . The outcome of the war was a major victory for the Turkish military establishment , which had been responsible for al - Mu ' tazz ' s rise to power , and allowed the Turks to maintain their effective power over the government and military of the caliphate . The partisans of al - Musta ' in , namely the Tahirid family , the Arab military factions , and the citizens of Baghdad , continued to be excluded from the politics of the central government after their surrender , although they were allowed to keep the positions they had before the war . Central Iraq , where most of the fighting took place , was devastated by the activities of both sides . The historian al - Tabari provided a lengthy and detailed account of the war . Other Muslim historians , such as al - Mas ' udi and al - Ya ' qubi , also mentioned the war in their works . Background . The caliph al - Mutawakkil ( 847 - 861 ) had created a plan of succession that would allow his sons to inherit the caliphate after his death ; he would be succeeded first by his eldest son , al - Muntasir , then by al - Mu ' tazz and third by al - Mu ' ayyad . In 861 al - Mutawakkil was assassinated by a group of Turkish military officers , likely with the support of al - Muntasir . During al - Muntasir ' s short reign ( 861 - 862 ) , the Turks pressured him into removing al - Mu ' tazz and al - Mu ' ayyad from the succession . When al - Muntasir died , the Turkish officers gathered together and decided to install the dead caliph ' s cousin al - Musta ' in on the throne . The new caliph was almost immediately faced with a large riot in Samarra in support of the disenfranchised al - Mu ' tazz ; the rioters were put down by the military but casualties on both sides were heavy . Al - Musta ' in , worried that al - Mu ' tazz or al - Mua ' yyad could press their claims to the caliphate , first attempted to buy them off and then threw them in prison . After the suppression of al - Mu ' tazz ' s supporters , the caliph ' s reign continued largely unabated until 865 . The continual inability of the government to pay the soldiers , however , combined with infighting among the ranks of the Turks , threatened the stability of the regime . At the beginning of 865 , a quarrel among the Turkish officers broke out , and the general soldiery quickly became involved . When one of the officers was killed , the soldiers turned violent , and soon they were rioting throughout the streets of Samarra . Faced with this hostile situation , al - Musta ' in and two of the senior Turkish officers , Wasif and Bugha al - Sharabi , decided to leave Samarra for Baghdad , where they were arrived in the first week of February 865 . Upon their arrival , they greeted by the city ' s powerful governor , Muhammad b . ' Abdallah , in whose palace the caliph took up his residence . When the Turks in Samarra realized that al - Musta ' in had departed from the city , they cut off traffic to Baghdad . A delegation of Turks then went to see the caliph ; when they arrived , they asked for forgiveness for their actions and for the caliph to return with them to Samarra . Al - Musta ' in , while promising the Turks that they would continue to be paid , refused to leave Baghdad , and he and Muhammad b . ' Abdallah mocked them for their perceived insolence . The humiliated Turks angrily returned to Samarra and told their compatriots what had happened ; they then decided to depose al - Musta ' in . The soldiers released al - Mu ' tazz from his prison and acknowledged him as their caliph . Al - Mu ' tazz agreed to the proposal and an oath of allegiance was drawn up ; many of the officials in Samarra then swore allegiance to him . Beginning of hostilities . With two members of the Abbasid family now claiming to be caliph , war became inevitable . On al - Musta ' in ' s side , Muhammad b . ' Abdallah quickly took command of the military effort . He ordered that all food shipments from Baghdad to Samarra be halted , and instructed allies in the Mosul region to do the same . Letters were sent by Muhammad to friendly commanders calling on them to mobilize their forces , and a recruitment drive was initiated in Baghdad . In preparation for a siege , the city was fortified , with the work being completed by February 22 . The bridges and canals around al - Anbar were destroyed , flooding the area and hindering any possible enemy troop movements there . Muhammad also wrote to the tax officials throughout the empire , instructing them that their revenues were to be sent to Baghdad instead of Samarra . For his part , al - Mu ' tazz wrote to Muhammad , urging him to declare allegiance to him . Soon after , al - Mu ' tazz put his brother Abu Ahmad ( the later al - Muwaffaq ) in command of an army and instructed him to fight against al - Musta ' in and Muhammad . The army , consisting of five thousand Turkish and Ferghana n ( " Faraghinah " ) soldiers under the leadership of Kalbatikin al - Turki and two thousand North African ( " Magharibah " ) soldiers under the leadership of Muhammad b . Rashid al - Maghribi , departed Samarra on February 24 . Six days later they arrived in Ukbara , where Abu Ahmad led the prayers in the name of al - Mu ' tazz . The Turks and North Africans began looting the area between Ubkara and Baghdad , causing many of the local residents to abandon their estates and fields . On March 10 , Abu Ahmad and his army appeared before the Shammasiyah gate on the East side of Baghdad , and the siege of the city began . Strategies and Military Strength . Al - Musta ' in . Neither caliph participated in the direct military operations of the war . In Al - Musta ' in ' s case , he was generally content to leave the responsibility of conducting the war effort to Muhammad b . ' Abdallah . As commander , Muhammad opted for an overall defensive strategy . Relying on his position in Baghdad , he was reluctant to engage in any sort of offensive operations outside the city and its surrounding districts , even when he was advised by others to do so . While he did make an effort to securing the nearby towns that controlled access to the city , there is no mention of any attempt to attack Samarra . By staying within Baghdad and keeping the city ' s supply routes open , while at the same time cutting off foodstuffs and tax receipts meant for Samarra , Muhammad likely believed that he could outlast al - Mu ' tazz ' s armies . A massive amount of work was done to prepare Baghdad for a siege . Walls and trenches were constructed on both the east and west sides of the city , at a cost of over three hundred thousand dinars . Ballistas and mangonel s were installed on the walls , and " war engines " designed to hinder enemy movement were placed in front of the city gates . The market awnings were removed so as to prevent them from being set on fire , and the areas outside the city were ploughed so that the mud would entrap the attackers . A few days after the fighting began , Muhammad ordered the razing of a large area behind the walls , so that the defenders would have more room to operate in . Muhammad had numerous sources of manpower in his allies and in the people of 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 the succession arrangements he should have become caliph after the death of al - Muntasir . When he had signed away his rights to the caliphate in 862 , he had been under duress to do so , with the Turks threatening to kill him if he refused , and therefore he considered the deed of abdication to be void . He also sought to convince the people that they could switch their allegiance to him without breaking the oath they had taken to serve al - Musta ' in , and went through the effort to explain in detail how this could be done in a letter to Muhammad b . ' Abdallah . Al - Mu ' tazz was initially accommodating toward those in Samarra who opposed his bid for the caliphate , and did not compel anyone to swear the oath to him if they refused to do so . He did , however , write to commanders stationed throughout the empire requesting their support , and soon reinforcements were arriving in Samarra . As the conflict progressed , he steadily gained followers as members of al - Musta ' in ' s camp began to defect to him . He also made efforts to entice al - Musta ' in ' s officers , writing offers to them and promising substantial rewards if they would switch their allegiance to him . Al - Mu ' tazz ' s brother Abu Ahmad was put in charge of the Samarran forces at the beginning of the war . He was charged by the caliph with defeating al - Musta ' in and Muhammad b . ' Abdallah , and was given the authority to command the army in any manner he pleased . Abu Ahmad ' s overall strategy was to keep Baghdad under constant attack from his troops , and to gain the surrender of the city by either assaulting it or starving its inhabitants until they lost the will to fight any longer . Toward this end , al - Mu ' tazz sent armies to secure the neighboring towns that controlled access to Baghdad , and Abu Ahmad attempted to halt and seize any revenue shipments heading toward the city . The way in which Abu Ahmad ran the siege was not unquestionably accepted by al - Mu ' tazz , who reportedly wrote him a letter in the middle of the war complaining of his lack of progress in forcing al - Musta ' in ' s capitulation , but he remained in command of the main besieging force throughout the entire conflict . Abu Ahmad ' s army at the beginning of the siege numbered approximately 7 , 000 soldiers . Additional troops sent from Samarra a short time later increased its size to 11 , 000 , though a large number of the reinforcements were killed soon after their arrival . At a later point in the war , a spy for Muhammad b . ' Abdallah reported that the besieging armies on the East and West sides of Baghdad totaled 19 , 000 men , and that al - Mu ' tazz had very few additional troops to put in the field , since Samarra had been almost completely emptied of soldiers . Major Events of the War . Fighting during the war lasted for slightly less than a year , with hostile engagements occurring everywhere from the Jazira in the north to the borders of Khuzestan in the southeast . Most of the battles of the war , however , took place in Iraq ; specifically at Baghdad , where al - Musta ' in had made his residence , and the districts surrounding the city . Baghdad . For the first few days after the arrival of Abu Ahmad and his army before the gates of Baghdad , the two sides refrained from directly engaging each other in combat . On March 14 , Muhammad b . ' Abdallah approached the enemy camp and called on the Samarrans to depart ; if they did , he guaranteed that al - Musta ' in would recognize al - Mu ' tazz as heir - apparent . If they refused to leave , however , Muhammad intended to initiate hostilities the following morning . The next day , the Samarrans approached the Shammasiyyah and Khorasan gates along the eastern wall and attempted to force their way through them . The Baghdadis responded by firing upon them with arrows , mangonels and ballistas , inflicting heavy casualties upon the attackers . At the Khorasan Gate , the Turks attempted to move up an artillery piece into firing range , but a charge by the regular and irregular Baghdadi forces dislodged the enemy from their position . By the end of the day , the Samarrans withdrew back to their camp ; both sides had sustained hundreds of casualties from the fighting . On March 20 a second army sent from Samarra , consisting of 4 , 000 Turks , North Africans and Ferghanans , arrived in front of the western side of Baghdad and made camp near the Gates of the Fief and Qatrabbul . The next morning , Muhammad b . ' Abdallah ordered a large contingent of infantry and cavalry to battle them . At first the Samarrans had the upper hand , and were able to force the Baghdadis into a narrow area near the Gate of the Fief . Baghdadi reinforcements soon arrived , however , and the combined forces were able to drive the Samarrans back . Having gained the initiative , the defenders charged and forced the Samarrans to retreat to an area where yet another Baghdadi force lay in ambush . At this point , the Samarran retreat turned into a rout , and the troops began to flee for their lives . Many attempted to swim across the Tigris to Abu Ahmad ' s camp , but were seized by boats patrolling the river . The rest turned north , with some of the soldiers going all the way back to Samarra . The battle for the Qatrabbul Gate had been a massive victory for the Baghdadis . Of the four thousand Samarrans stationed on the western side of the city , two thousand of them had been killed , with several of their heads being hung around Baghdad , and many others were taken prsioner . In Samarra , news of the defeat was met with rioting ; many among the populace apparently considered the battle to be a sign of the weakness of al - Mu ' tazz ' s forces . Muhammad b . ' Abdallah , however , refused to follow up on his victory . Rejecting the council of his advisors to press his advantage and pursue the fleeing soldiers , his only order after the battle was to have proclamation of victory drawn up and read in the Jama Mosque of the Round City . Meanwhile Abu Ahmad ' s army , which is not mentioned as having participated in the battle that day , remained encamped on the eastern side . As a result , the siege of the city continued . After the battle for the Qatrabbul Gate , the siege effectively turned into a stalemate . Throughout the late spring and summer , the Samarrans and Baghdadis regularly engaged each other around the defensive fortifications of the city and inflicted many casualties on each other , but neither side was able to gain a clear advantage . Over the following months , the fighting spread to the districts neighboring Baghdad , as both sides fought to control the routes leading into the city . The Samarrans were able to limit the level of supplies reaching the defenders , but were unable to prevent the Baghdadi armies from moving in and out of the city . The stalemate around Baghdad remained unbroken until early September . On the morning of September 8 , however , the Samarran armies on both sides of the city engaged in a major assault on the fortifications . While the Samarrans on the eastern side attacked the Shammasiyyah Gate , the Turks and North Africans on the western side managed to punch through the initial line of defenses and advance to the Anbar Gate . Despite being caught unaware , the defenders at the Anbar Gate put up a staunch resistance , but eventually they were forced to retreat and the Anbar Gate was set on fire . The Samarrans then entered Baghdad and spread throughout the Harbiyah quarter of the city , setting fire to the areas that they entered . The residents of the neighborhoods that the Samarrans passed through fled for their lives , and the Samarran troops planted flags in the parts of the city that they conquered . In response to the assault Muhammad b . ' Abdallah gathered his commanders together , and then sent men to the gates all along the western side of the city . The reinforcements engaged the Samarrans and , after killing a large number of them , forced them back to the gateways . Fighting continued until the late afternoon , with the defenders finally managing to expel the Samarrans from the gates and forcing them to flee back to their camp . The areas in the wall where the Samarrans had broken through were ordered repaired . The assault on the eastern side of the city also failed , as the Baghdadis were able to force the attackers back . As with the fighting on the western side , many Baghdadi and Samarran soldiers were killed in the battle for the Shammasiyyah Gate . The assault having therefore failed , the Samarrans returned to their siege positions . As the siege continued into autumn , Muhammad worked with his lieutenants to plan a sally in an attempt to break the stalemate . The mangonels and ballistas along the walls were prepared for action , and in late November the city gates were opened . The entire Baghdadi army then came out of the city , while river boats loaded with bowmen and artillery moved up the Tigris . They attacked the Samarran army and routed them , forcing them to flee . The Samarran camp was plundered and the irregulars began cutting off the heads of the slain . The Samarran position was saved only when Abu Ahmad made a stand and rallied the troops to regroup ; at the same time , the Baghdadis lost their focus and their charge stalled . The Samarrans soon returned to their camp , while the Baghdadis retreated back to the city . Al - Nahrawan . The town of al - Nahrawan lay just to the east of Baghdad . Its importance lay in the fact that it was the first stage on the road from Baghdad to Khorasan , the latter of which was governed by Muhammad b . ' Abdallah ' s nephew ; whoever controlled the town would therefore be able to stop or allow transportation between the two locations . Before the siege of Baghdad began , Muhammad b . ' Abdallah sent five hundred infantry and cavalry to al - Nahrawan to defend it against the Turks . Later , another seven hundred soldiers were dispatched to the town to reinforce the first group . On March 19 , nine days after Abu Ahmad had arrived in front of Baghdad , a force of Turks marched to al - Nahrawan challenge Muhammad ' s control of it . The defenders decided to meet the Turks on the field , and a battle ensued . The Turks soon gained the upper hand , and the defenders turned and fled to Baghdad . Fifty of the defenders had died in the battle , and the Turks sent their heads to Samarra , along with mounts and weapons that the defenders had abandoned . With the Turks victorious , they gained control of the Khorasan road , and traffic between there and Baghdad was cut off . When Muhammad learned of the defeat , he recalled troops stationed further down the road at Hamadan and ordered their return to Baghdad . Although Muhammad is not recorded as having made any attempts to retake al - Nahrawan , the town continued to suffer during the conflict . At some date after the battle , a group of Samarrans returning from deployment in the Jibal entered al - Nahrawan . For unstated reasons , the Samarran commander ordered his troops to plunder the town . The soldiers then began attacking the local residents , and most of the citizens were forced to flee . Al - Anbar and Qasr ibn Hubayrah . Al - Anbar , lying on the Euphrates to the west of Baghdad , was a major town in the early Abbasid era . At the outbreak of hostilities , Muhammad b . ' Abdallah ordered its ruler to prepare for its defense . The canals and bridges around the town were cut , and the surrounding area was turned into a large swamp . By the middle of spring the commander of al - Anbar had raised a force of several thousand Bedouin recruits , and he sent a request to Muhammad for reinforcements . Muhammad promptly ordered over a thousand more cavalry and infantry to depart for the town . In Samarra , meanwhile , plans were developed to attack al - Anbar , and soon al - Mu ' tazz sent a force of Turks and North Africans to take the town . The defense at al - Anbar was split into two groups , with the reinforcements stationed outside the town and the Bedouins within . When the Samarran army arrived before al - Anbar , they caught the reinforcements by surprise and quickly fell upon them . Some of the defenders put up a fight , but they soon fled , with many of them killed or becoming prisoners . When the commander of the town saw the reinforcements flee , he decided to abandon his post . He and his troops crossed over to the other side of the river , cut the pontoon bridge , and made their way back to Baghdad . With al - Anbar now lacking any defense , its residents decided to surrender on terms . After giving guarantees of safe conduct to the Anbaris , the Turks and North Africans entered the town , and allowed the people to go about their business . The next day , however , the soldiers seized a shipment of goods arriving from al - Raqqah and began looting the town . They sent the heads of the slain to Samarra , along with the prisoners that had been captured , and unsuccessfully attempted to dam a water route running between the Euphrates and Baghdad . When the defeated armies of al - Anbar arrived at Baghdad , Muhammad gave orders that the town was to be retaken . A contingent of troops was sent to Qasr ibn Hubayrah further down the Euphrates and awaited orders to advance . Meanwhile , an army of over a thousand men was raised in Baghdad and put under the command of al - Husayn b . Isma ' il , who was instructed to head directly to the town and defeat the Samarran garrison stationed there . After a delay caused by an issue with the troops ' pay , the army departed in late June . The Baghdadi army was assailed almost immediately after their departure by the Turks and North Africans , who attempted to prevent their reaching al - Anbar . In spite of stiff resistance , the Baghdadis were able to construct a bridge across a canal guarded by the Turks and fight them off , but after twelve days they had still failed to reach al - Anbar . Eventually the Turks , who had spies in the al - Husayn ' s army , were able to ambush their camp . Despite inflicting heavy casualties on the attackers , the Baghdadi army soon fell in disorder , and many of the soldiers were either killed or drowned in the Euphrates . The cavalry turned tail and fled , and when the officers realized that they had lost control of the situation they retreated as well . The Turks then plundered the enemy camp and rounded up the prisoners they had captured . Both sides suffered hundreds of dead and wounded from the fighting . The remnants of the defeated army retreated back to Baghdad , encamping in the city suburbs in the first week of July . Muhammad gave orders that al - Husayn was to be refused entry to Baghdad , and that any of al - Husayn ' s men that did not promptly leave the city for his camp would be flogged and denied pay . Al - Musta ' in also sent a letter to the encamped soldiers , chastising them for their failure and accusing them of disobedience and mutiny . Al - Husayn was told to gather his men and make another effort to retake al - Anbar . By mid - July , al - Husayn ' s forces were ready , and for the second time they headed to retake the town . Al - Husayn ' s second campaign was to end as badly as the first . Once again the Turks defending the land between Baghdad and al - Anbar attacked the Baghdadi army . Al - Husayn was able to fight them off for several days , but eventually the Turks were able to outmaneuver him and rout the guards stationed on his flanks . When they attacked al - Husayn ' s army itself , they quickly defeated his men and overran his camp . Al - Husayn himself managed to escape on a river skiff , but a hundred of his men were killed and 170 had been taken prisoner , including several of the officers . Al - Husayn and the other survivors returned to Baghdad , and there were no further attempts to retake al - Anbar . Qasr ibn Hubayrah , the other western town garrisoned by Muhammad ' s forces , was taken by the Turks shortly after . After the conquest of al - Anbar , the Samarran army headed to Qasr ibn Hubayrah and intended to expel the Baghdadis stationed there . Instead , its commander decided to flee the town , giving it up to the Turks without resisting . Al - Mada ' in . Al - Mada ' in , to the south of Baghdad in the direction of Wasit , was a series of settlements lying in the midst of the ancient Persian imperial centers of Ctesiphon and Seleucia . On April 21 , on the orders of Muhammad b . ' Abdallah , Abu ' l - Saj Dewdad departed Baghdad for al - Mada ' in at the head of three thousand cavalry and infantry units . He arrived in the area and settled his troops there . Later he wrote to Muhammad requesting reinforcements , which were sent to him . Over the course of the summer , the Turks began appearing in the vicinity of al - Mada ' in in strength . Abu ' l - Saj responding by advancing further south , to the district of Jarjaraya , where in August he defeated a contingent of Turks and killed their commander . In October he again fought the Turks near Jarjaraya and killed or captured a large number of them . Despite these victories , Abu ' l - Saj was reportedly unsatisfied with the performance of his troops during the fighting , and Muhammad arranged for more reinforcements to be sent to assist him . The reinforcements set out on October 23 and , after marching the entire day , arrived at al - Mada ' in just as an army of Turks also appeared before the city . Combat between the two sides began , but the defenders were quickly overwhelmed when the Turks found a breach in the city wall and forced their way through it . The defenders tried to implement an orderly retreat , with the infantry being loaded onto boats and moved along the river while the cavalry covered their withdrawal , but the Turks continued to engage them and the commander of the reinforcements died in the chaos . With al - Mada ' in now lost to them , the survivors made their way to Abu ' l - Saj ' s camp . Muhammad was angered by the result of the battle , and ordered several of those who had fought at al - Mada ' in to be placed under house arrest . End of the War . As the siege of Baghdad wore on , it began to have its intended effect . Food and money slowly became scarce , and discontent among the populace began to emerge . As early as August , a group of members of the Abbasid family complained to Muhammad b . ' Abdallah that their stipends were not being paid . As conditions in the city deteriorated , Muhammad gradually became convinced that victory through force of arms was impossible . By November at the latest , and without the knowledge or permission of al - Musta ' in , he had opened negotiations with al - Mu ' tazz regarding al - Musta ' in ' s surrender . Muhammad and al - Mu ' tazz had already started negotiating with each other when the former launched his failed sally . After the battle , al - Mu ' tazz criticized Muhammad for acting in bad faith , and the Samarran army intensified the siege . Soon the city was running low on resources . Crowds began appearing before Muhammad ' s palace , crying " hunger ! " and demanding a resolution to their problems . Muhammad held off the crowds with promises , and at the same time sent an offer of peace to al - Mu ' tazz . This was responded to favorably , and beginning on December 8 a representative from Abu Ahmad ' s camp began meeting Muhammad in private to discuss how to end the conflict . As the siege progressed into December , the population of Baghdad became more agitated . On December 16 , some of the regular infantry and commoners gathered together , with the former demanding their pay and the latter complaining about how food prices had skyrocketed . Muhammad was able to convince them to temporarily disperse , but riots broke out in the city two days later and it was only with difficulty that they were quelled . Meanwhile negotiations between Muhammad and Abu Ahmad continued ; emissaries were sent by Muhammad to Abu Ahmad ' s camp , and Samarran prisoners of war were released . Toward the end of December , a provisional agreement between the two sides to depose al - Musta ' in was reached , and Abu Ahmad sent five ships loaded with foodstuffs and fodder to relieve the shortages in the city . When the citizens of Baghdad learned that Muhammad had agreed to depose al - Musta ' in , they angrily assembled outside his palace . Out of loyalty to al - Musta ' in and fears that Muhammad ' s surrender could result in the Samarrans plundering the city , they attacked the palace gates and fought against the guards . In order to calm the protestors , al - Musta ' in appeared above the palace gate with Muhammad at his side , and he gave assurances to the crowd that he was still caliph and that he would lead the Friday prayers the next morning . The following day , December 28 , he failed to appear ; in response , the houses of Muhammad ' s subordinates were looted and a large crowd again approached Muhammad ' s palace , forcing al - Musta ' in to make another public appearance . Shortly after this he moved out of Muhammad ' s palace to another residence in the city , and on January 2 , 866 , he led the prayer for the Feast of Sacrifice . Muhammad , for his part , strove to convince the people that he was still acting in al - Musta ' in ' s best interests , while at the same time continuing to negotiate with Abu Ahmad regarding the terms of surrender . On January 7 , Muhammad and Abu Ahmad met in person under a canopy outside the Shammasiyah gate , and the two men agreed that the state revenues would be split among the parties , with two thirds going to the Turks and one third going to Muhammad and the Baghdadi army , and al - Musta ' in should be held liable for part of the soldiers ' pay . On the following day , Muhammad went to al - Musta ' in and attempted to convince him to abdicate . At first al - Musta ' in adamantly refused , but when the Turkish officers Wasif and Bugha stated that they had sided with Muhammad , he agreed to step down . As part of the terms of al - Musta ' in ' s abdication , he was to be given an estate in the Hijaz , and allowed to travel between the cities of Mecca and Medina . On January 12 , Muhammad brought a group of judges and jurists to witness that al - Musta ' in had entrusted his affairs to him . Delegates carrying the terms of abdication were sent to Samarra , where al - Mu ' tazz personally signed the document and agreed to the conditions . The delegates returned to Baghdad with the signed document on January 24 , accompanied by a group of emissaries sent to secure al - Musta ' in ' s allegiance to al - Mu ' tazz . On Friday , January 25 , al - Mu ' tazz was acknowledged as caliph in the mosques throughout Baghdad . Aftermath . The outcome of the war did nothing to solve the problems that had been responsible for it in the first place . The revenues of the state were still massively insufficient to pay the soldiers ' salaries , causing violence to break out among the troops . The military continued to demand complete control over the affairs of the state , and met with hostility the attempts to the caliphs to reduce their authority . As a result , the government soon reverted to the state of instability it had been in before the war . The war was , at least economically speaking , extremely destructive for the empire . The costs of campaigning for both sides , including paying for soldiers ' and officers ' salaries and other wartime expenses , was enormous . The cutting of the canals around al - Anbar contributed to a long term economic decline in the region , and the numerous acts of plunder and forcing people from their fields disrupted the productivity of the empire ' s richest province , putting additional financial strain on the state . Baghdad was devastated , with the eastern side of the city never fully recovering from the damage it incurred during the war . Within the city , the populace had gone several months without adequate supplies , and price inflation and deprivation became common . The human cost of the war is difficult to determine , since no comprehensive casualty figures are mentioned , but at the very least it ranged in the thousands . In spite of the terms of abdication , al - Musta ' in was not allowed to go into exile to the Hijaz , but was instead moved to Wasit . In October 866 he was ordered to travel to Samarra , but on October 17 , when he had arrived in the vicinity of the city , he was intercepted by a group of men sent to kill him and was quickly executed . Al - Mu ' tazz ' s caliphate after the war was to prove to be short and violent . His brothers Abu Ahmad , who had been responsible for his victory in the war , and al - Mu ' ayyad were both thrown in prison in 866 , with al - Mu ' ayyad dying a short time later . Meanwhile , infighting among the military soon flared up again , and numerous officers , including Wasif and Bugha , were killed . Finally , due to the inability of the caliph to pay them , in July 869 a group of Turkish , North African and Ferghanan soldiers forced al - Mu ' tazz to abdicate and he died from maltreatment a few days later . The only member of the Abbasid family to benefit from the conflict in the long term was Abu Ahmad . He developed strong connections with the Turkish leadership , and this relationship was what possibly prevented al - Mu ' tazz from killing him when he was imprisoned the following year . In spite of his imprisonment and subsequent exile , he remained a powerful figure in the government and was a possible contender for the caliphate in 869 . From the ascension of al - Mu ' tamid in 870 , he was the de facto ruler of the empire with the title of al - Muwaffaq , although he never formally became caliph . Thanks to his close ties to the Turks , he became the chief military commander of the state . His son al - Mu ' tadid actually did become caliph in 892 , and all subsequent Abbasid caliphs were descended from him . Al - Musta ' in ' s defeat resulted in Samarra remaining the capital city of the caliphate . It would continue to serve as such until 892 , during the caliphate of al - Mu ' tadid ; thereafter the seat of the caliphs remained at Baghdad .