Editing Al-Mu'tasim (section)

=== Confrontation with Byzantium ===
{{main|Sack of Amorium|Battle of Anzen}}
[[File:Byzantine-Arab wars, 837-838.svg|thumb|right|upright=1.2|alt=Geophysical map of Anatolia with the major cities and movements of the Byzantine and Arab armies marked|Map of the Byzantine and Abbasid campaigns in the years 837–838, showing [[Theophilos (emperor)|Theophilos]]'s raid into [[Upper Mesopotamia]] and al-Mu'tasim's retaliatory invasion of [[Asia Minor]], culminating in the conquest of [[Amorium]].]]
Taking advantage of the Abbasids' preoccupation with the suppression of the Khurramite rebellion, the Byzantine emperor Theophilos had launched attacks on the Muslim frontier zone in the early 830s, and scored several successes. His forces were bolstered by some 14,000 Khurramites who fled into the Empire, became baptized and enrolled in the Byzantine army under the command of their leader Nasr, better known by his Christian name [[Theophobos]].{{sfn|Treadgold|1988|pp=280–283}} In 837, Theophilos, urged by the increasingly hard-pressed Babak, launched a major campaign into the Muslim frontier lands. He led a large army, reportedly numbering over 70,000 men, in an almost unopposed invasion of the region around the upper [[Euphrates]]. The Byzantines took the towns of [[Zibatra]] (Sozopetra) and [[Arsamosata]], ravaged and plundered the countryside, extracted ransom from [[Malatya]] and other cities in exchange for not attacking them, and defeated several smaller Arab forces.{{sfn|Treadgold|1988|pp=286, 292–294}}{{sfn|Vasiliev|1935|pp=137–141}} As refugees began arriving at Samarra, the caliphal court was outraged by the brutality and brazenness of the raids; not only had the Byzantines acted in open collusion with the Khurramites, but during the sack of Zibatra all male prisoners were executed and the rest of the population sold into slavery, and some captive women were raped by Theophilos' Khurramites.{{sfn|Treadgold|1988|pp=293–295}}{{sfn|Vasiliev|1935|pp=141–143}}

The Caliph took personal charge of preparations for a retaliatory expedition, as the campaigns against Byzantium were customarily the only ones in which caliphs participated in person.{{sfn|Kennedy|2004a|p=164}} Al-Mu'tasim assembled a huge force—80,000 men with 30,000 servants and camp followers according to [[Michael the Syrian]], or even larger according to other writers—at [[Tarsus (city)|Tarsus]]. He declared his target to be [[Amorium]], the birthplace of the reigning Byzantine dynasty. The Caliph reportedly had the name painted on the shields and banners of his army. The campaign began in June, with a smaller force under al-Afshin attacking through the Pass of [[Hadath]] in the east, while the Caliph with the main army crossed the Cilician Gates from 19 to 21{{spaces}}June. Theophilos, who had been caught unaware by the two-pronged Abbasid attack, tried to confront al-Afshin's smaller force first, but suffered a major defeat at the [[Battle of Dazimon]] on 22{{spaces}}July, barely escaping with his life. Unable to offer any effective resistance to the Abbasid advance, the Emperor returned to Constantinople. A week later, al-Afshin and the main caliphal army joined forces before [[Ancyra]], which had been left defenceless and was plundered.{{sfn|Treadgold|1988|pp=297–302}}{{sfn|Vasiliev|1935|pp=144–160}}{{sfn|Bosworth|1991|pp=97–107}}

[[File:Byzantine emissaries to the Caliph.jpg|thumb|Byzantine envoys before al-Mu'tasim (seated, right), miniature from the ''[[Madrid Skylitzes]]'' (12th/13th century)]]
From Ancyra, the Abbasid army turned to Amorium, to which they laid siege on 1{{spaces}}August. Al-Afshin, Itakh, and Ashinas all took turns assaulting the city with their troops, but the siege was fiercely contested, even after the Abbasids, informed by a defector, effected a breach in a weak spot of the wall. After two weeks, taking advantage of a short truce for negotiations requested by one of the Byzantine commanders of the breach, the Abbasid army successfully stormed the city. It was thoroughly plundered and its walls razed, while the populace, numbering into the tens of thousands, was carried off to be sold into slavery.{{sfn|Treadgold|1988|pp=302–303}}{{sfn|Vasiliev|1935|pp=160–172}}{{sfn|Bosworth|1991|pp=107–117}} According to al-Tabari, al-Mu'tasim was now considering extending his campaign to attack Constantinople, when the conspiracy headed by his nephew, al-Abbas, was uncovered. Al-Mu'tasim was forced to cut short his campaign and return quickly to his realm, without bothering with Theophilos and his forces, stationed in nearby [[Dorylaion]]. Taking the direct route from Amorium to the Cilician Gates, both the Caliph's army and its prisoners suffered during the march through the arid countryside of central Anatolia. Some captives were so exhausted that they could not move and were executed, while others found in the turmoil the opportunity to escape. In retaliation, al-Mu'tasim, after separating the most prominent among them, executed the rest, some 6,000.{{sfn|Treadgold|1988|p=303}}{{sfn|Vasiliev|1935|pp=172–173}}{{sfn|Bosworth|1991|pp=118–119}}

[[File:Siege of Amorium.jpg|250px|thumb|Miniature depicting the [[sack of Amorium]] in 838]]
The sack of Amorium brought al-Mu'tasim much acclaim as a warrior-caliph and ''[[Ghazi (warrior)|ghāzī]]'' (warrior for the faith), and was celebrated by contemporaries, most notably in a famous ode by the court poet [[Abu Tammam]].{{sfn|Bosworth|1993|p=776}} The Abbasids did not follow up on their success. Warfare continued between the two empires with raids and counter-raids along the border, but after a few Byzantine successes a truce was agreed in 841. At the time of his death in 842, al-Mu'tasim was preparing yet another large-scale invasion, but the great fleet he had prepared to assault Constantinople was destroyed in a storm off [[Cape Chelidonia]] a few months later. Following al-Mu'tasim's death, warfare gradually died down, and the [[Battle of Mauropotamos]] in 844 was the last major Arab–Byzantine engagement for a decade.{{sfn|Vasiliev|1935|pp=175–176, 192–193, 198–204, 284}}