Abū Isḥāq Muḥammad ibn Hārūn al-Rashīd (Arabic: أبو إسحاق محمد بن هارون الرشيد; October 796 – 5 January 842), better known by his regnal name al-Muʿtaṣim biʾllāh (المعتصم بالله, lit.

The Arab and Iranian elites that had played a major role in the early period of the Abbasid state were increasingly marginalized, and an abortive conspiracy against al-Mu'tasim in favour of al-Abbas in 838 resulted in a widespread purge of their ranks.

The two major internal campaigns of the reign were against the long-running Khurramite uprising of Babak Khorramdin in Adharbayjan, which was suppressed by al-Afshin in 835–837, and against Mazyar, the autonomous ruler of Tabaristan, who had clashed with the Tahirid governor of Khorasan and risen up in revolt.

The abrupt downfall of the powerful Barmakid family, which had dominated government during the previous decades, in 803 hinted at political instability at the highest levels of the court, while provincial rebellions that were suppressed with difficulty provided warning signals about the dynasty's hold over the empire.

The revenues of the provinces kept the treasury full, allowing Harun to launch huge expeditions against the Byzantine Empire and engage in vigorous diplomacy, his envoys arriving even at the distant court of Charlemagne.

This event made al-Ma'mun realise his inability to rule from afar; bowing to popular reaction, he dismissed or executed his closest lieutenants, and returned in person to Baghdad in 819 to begin the difficult task of rebuilding the state.

[29] Along with the abnāʾ, the old Arab families settled in the provinces since the time of the Muslim conquests, and the members of the extended Abbasid dynasty formed the core of the traditional elites and largely supported al-Amin.

[32][33] Abu Ishaq's Turkish corps was politically useful to al-Ma'mun, who tried to lessen his own dependence on the mostly eastern Iranian leaders, such as the Tahirids, who had supported him in the civil war, and who now occupied the senior positions in the new regime.

[42] According to a most likely fanciful[43] story provided by the 10th-century chronicler al-Tabari, Ashinas, in later years one of the chief Turkish leaders, received his name when he placed himself between a Kharijite lancer about to attack the future caliph, shouting, "Recognize me!"

[42] In 828, al-Ma'mun appointed Abu Ishaq as governor of Egypt and Syria in place of Abdallah ibn Tahir, who departed to assume the governorship of Khurasan, while the Jazira and the frontier zone (thughūr) with the Byzantine Empire passed to al-Abbas.

[12] According to the account of al-Tabari, on his deathbed al-Ma'mun dictated a letter nominating his brother, rather than al-Abbas, as his successor,[56] and Abu Ishaq was acclaimed as caliph on 9 August, with the regnal name of al-Mu'tasim (in full al-Muʿtaṣim bi’llāh, "he who seeks refuge in God").

[60][61][62] Whatever the true background of his accession, al-Mu'tasim owed his rise to the throne not only to his strong personality and leadership skills, but principally to the fact that he was the only Abbasid prince to control independent military power, in the form of his Turkish corps.

[31] The reforms of al-Mu'tasim completed this process, resulting in the eclipse of the previous Arab and Iranian elites, both in Baghdad and the provinces, in favour of the Turkish military, and an increasing centralization of administration around the caliphal court.

Al-Mu'tasim discontinued the practice, removing the Arab families from the army registers (diwān) and ordering that the revenues of Egypt be sent to the central government, which would then pay a cash salary (ʿaṭāʾ) only to the Turkish troops stationed in the province.

This measure was probably intended to allow his chief followers immediate access to funds with which to pay their troops, but also, according to Kennedy, "represented a further centralizing of power, for the under-governors of the provinces seldom appeared at court and played little part in the making of political decisions".

[65] Indeed, al-Mu'tasim's caliphate marks the apogee of the central government's authority, in particular as expressed in its right and power to extract taxes from the provinces, an issue that had been controversial and had faced much local opposition since the early days of the Islamic state.

[68][69] His replacement, Muhammad ibn al-Zayyat, was of a completely different character: a rich merchant, he is described by Kennedy as "a competent financial expert but a callous and brutal man who made many enemies", even among his fellow members of the administration.

Headed by Ujayf ibn Anbasa, a long-serving Khurasani who had followed al-Ma'mun since the civil war against al-Amin, the conspiracy rallied the traditional Abbasid elites, dissatisfied with al-Mu'tasim's policies and especially his favouritism towards the Turks.

According to Tayeb El-Hibri it allowed the court to exist "at a distance from the populace of Baghdad and protected by a new guard of foreign troops, and amid a new royal culture revolving around sprawling palatial grounds, public spectacle and a seemingly ceaseless quest for leisurely indulgence", an arrangement compared by Oleg Grabar to the relationship between Paris and Versailles after Louis XIV.

[88][89] By creating a new city in a previously uninhabited area, al-Mu'tasim could reward his followers with land and commercial opportunities without cost to himself and free from any constraints, unlike Baghdad with its established interest groups and high property prices.

Poorly sited in terms of water supply and river communications, its existence was determined solely by the presence of the caliphal court, and when the capital returned to Baghdad, sixty years later, Samarra was rapidly abandoned.

Among the notable scholars active during his reign were the astronomers Habash al-Hasib al-Marwazi[94][95] and Ahmad al-Farghani,[95] the polymath al-Jahiz,[96] and the distinguished Arab mathematician and philosopher al-Kindi, who dedicated his work On First Philosophy to his patron al-Mu'tasim.

[101] Ideologically, al-Mu'tasim followed the footsteps of al-Ma'mun, continuing his predecessor's support for Mu'tazilism, a theological doctrine that attempted to tread a middle way between secular monarchy and the theocratic approach espoused by the Alids and the various sects of Shi'ism.

[108] With the exception of the Amorium campaign, most of the military expeditions of al-Mu'tasim's reign were domestic, directed against rebels in areas that, although nominally part of the Caliphate, had remained outside effective Muslim rule and where native peoples and princes retained de facto autonomy.

[108] The three great campaigns of the reign—Amorium, the expedition against the Khurramite rebellion, and that against Mazyar, ruler of Tabaristan—were in part also conscious propaganda exercises, in which al-Mu'tasim could solidify his regime's legitimacy in the eyes of the populace by leading wars against infidels.

A succession of military commanders attempted to subdue the rebellion on their own initiative, and thus gain control of the country's newly discovered mineral resources, only to be defeated by the Khurramites under the capable leadership of Babak.

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.

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 July, barely escaping with his life.

[151] With his Turkish guard, al-Mu'tasim set a pattern that would be widely imitated: not only did the military acquire a predominant position in the state, but it also increasingly became the preserve of minority groups from the peoples living on the margins of the Islamic world.

Less than a century after al-Mu'tasim's death, this process would lead to the bankruptcy of the Abbasid government and the eclipse of the caliphs' political power with the rise of the Khazar officer Ibn Ra'iq to the position of amīr al-umarāʾ.