Editing Abbasid Caliphate (section)

==History==
===Abbasid Revolution (747–750)===
{{main|Abbasid revolution}}
The Abbasid caliphs were descended from [[Abbas ibn Abd al-Muttalib]], one of the youngest uncles of [[Muhammad]] and of the same [[Banu Hashim]] clan. The Abbasids claimed to be the true successors of Muhammad in replacing the Umayyad descendants of [[Umayya ibn Abd Shams|Banu Umayya]] by virtue of their closer bloodline to Muhammad.

The Abbasids also distinguished themselves from the Umayyads by attacking their moral character and administration in general. According to [[Ira Lapidus]], "The Abbasid revolt was supported largely by Arabs, mainly the aggrieved settlers of [[Merv]] with the addition of the Yemeni faction and their [[Mawali]]".{{sfn|Lapidus|2002|p=54}} The Abbasids also appealed to [[Ajam|non-Arab]] Muslims, known as ''mawali'', who remained outside the kinship-based society of the Arabs and were perceived as a lower class within the Umayyad empire. [[Mohammad ibn Ali Abbasi|Muhammad ibn 'Ali]], a great-grandson of Abbas, began to campaign in Persia for the return of power to the family of Muhammad, the [[Banu_Hashim|Hashemites]], during the reign of [[Umar II]].

During the reign of [[Marwan II]], this opposition culminated in the rebellion of [[Ibrahim al-Imam]], the fourth in descent from Abbas. Supported by the province of [[Greater Khorasan|Khurasan]] (eastern Iran), even though the governor opposed them, and the Shia Arabs,<ref name=":11" />{{sfn|Dupuy|Dupuy|1986|p=233}} he achieved considerable success, but was captured in the year 747 and died, possibly assassinated, in prison.

On 9 June 747 (15 Ramadan AH 129), [[Abu Muslim]], rising from Khurasan, successfully initiated an open revolt against Umayyad rule, which was carried out under the sign of the [[Black Standard]]. Close to 10,000 soldiers were under Abu Muslim's command when the hostilities officially began in Merv.{{sfn|Lewis|1995|p=102}} [[Qahtaba ibn Shabib al-Ta'i|General Qahtaba]] followed the fleeing governor [[Nasr ibn Sayyar]] west defeating the Umayyads at the Battle of Gorgan, the Battle of Nahavand and finally in the Battle of Karbala, all in the year 748.{{sfn|Dupuy|Dupuy|1986|p=233}}

Ibrahim was captured by Marwan and was killed. The quarrel was taken up by Ibrahim's brother Abdallah, known by the name of [[Abu al-'Abbas as-Saffah]], who defeated the Umayyads in 750 in the [[Battle of the Zab|battle near the Great Zab]] and was subsequently proclaimed [[caliph]].<ref name="EB1911">{{Cite EB1911|wstitle= Abbasids|volume=1|page=10}}</ref> After this loss, Marwan fled to Egypt, where he was subsequently killed. The remainder of his family, barring one male, were also eliminated.{{sfn|Dupuy|Dupuy|1986|p=233}}

===Establishment and consolidation (750–775)===
[[File:Balami - Tarikhnama - Abu'l-'Abbas al-Saffah is proclaimed the first 'Abbasid Caliph (cropped).jpg|thumb|Early 14th century copy of the [[Samanids|Samanid]]-period ''[[Tarikhnama]]'' of [[Muhammad Bal'ami|Bal'ami]] (10th century) depicting [[al-Saffah]] ({{Reign|750|754}}) as he receives [[Bay'ah|pledges of allegiance]] in [[Kufa]]|left]]
Immediately after their victory, al-Saffah ({{Reign|750|754}}) sent his forces to [[Central Asia]], where his forces fought against [[Tang dynasty|Tang]] expansion during the [[Battle of Talas]]. Al-Saffah focused on putting down numerous rebellions in Syria and [[Mesopotamia]]. The [[Byzantine Empire|Byzantines]] conducted raids during these early distractions.{{sfn|Dupuy|Dupuy|1986|p=233}}

One of the first major changes effected by Abbasid rule was the move of the caliphate's center of power from Syria to Mesopotamia (present-day Iraq). This was closer to the Persian ''mawali'' support base of the Abbasids and the move addressed their demand for reduced Arab dominance in the empire.<ref name="AHGC">{{harvnb|University of Calgary|1998}}</ref> However, no definitive capital was yet selected. In these early Abbasid years, [[Kufa]] generally served as the administrative capital, but the caliphs were wary of the [[Alid]] sympathies in the city and did not always reside here.<ref name="Kufa">{{Encyclopaedia of Islam, Second Edition|volume=5|article=al-Kūfa|first=Hichem|last=Djaït|page=347}}</ref> In 752, al-Saffah built a new city called al-Hashimiyya, at an uncertain location, most likely near Kufa.<ref name="Hashimiyya">{{Encyclopaedia of Islam, Second Edition|volume=3|pages=265-266|first=J.|last=Lassner|article=al-Hās̲h̲imiyya}}</ref> Later that same year, he moved to [[Anbar (town)|Anbar]], where he built a new settlement for his Khurasani soldiers and a palace for himself.<ref>{{EI2|volume=1|article=al-Anbār|first1=M.|last1=Streck|first2=A.A.|last2=Duri|page=485}}</ref>

[[File:Abbāsid Caliph al-Manṣūr from the genealogy (silsilanāma), Cream of Histories (Zübdet-üt Tevarih, 1598).jpg|thumb|Portrait of [[al-Mansur]] ([[Reign|r.]] 754–775) from an [[Ottoman Empire|Ottoman]]-era work, the "Cream of Histories" (''Zübdet-üt Tevarih'') in 1598<ref>{{Cite web |title=Portraits of the Imāms Ḥasan (d. 670), Ḥusayn (d. 680), Shāfi'ī (d. 820) and Abū Ḥanīfa (d. 767), with 'Abbāsid revolutionary Abū Muslim (d. 755) (recto), and 'Abbāsid Caliphs al-Manṣūr, Hārūn al-Rashīd and al-Ma'mūn, with rulers Būya and Aḥmad Sāmānī (verso), from the genealogy (silsilanāma), Cream of Histories (Zübdet-üt Tevarih) |url=https://viewer.cbl.ie/viewer/image/T_423_22/2/ |access-date=6 March 2025 |website=Chester Beatty Library}}</ref>]]
It was al-Saffah's successor, [[Abu Ja'far al-Mansur]] ({{Reign|754|775}}) who firmly consolidated Abbasid rule and faced down internal challenges.{{sfn|El-Hibri|2021|pp=43-55}} His uncle, [[Abd Allah ibn Ali|Abdallah ibn Ali]], the victor over the Umayyads at the Battle of the Zab, was the most serious potential rival for leadership and al-Mansur sent Abu Muslim, the Khurasani revolutionary commander, against him in 754. After Abu Muslim successfully defeated him, al-Mansur then turned to eliminate Abu Muslim himself. He arranged to have him arrested and executed in 755.{{sfn|El-Hibri|2021|pp=43-45}}

On the western frontier, the Abbasids were unable to re-assert caliphal control over the western and central [[Maghreb]], which the Umayyads had lost in the 740s.{{sfn|Abun-Nasr|1987|p=41}} One member of the Umayyad dynasty, Abd ar-Rahman, also managed to escape the purge of his family and established independent rule in [[al-Andalus]] (present-day Spain and Portugal) in 756, founding the Umayyad [[Emirate of Córdoba]].{{sfn|El-Hibri|2021|pp=41, 86}}

In 756, al-Mansur had also sent over 4,000 Arab mercenaries to assist the Chinese [[Tang dynasty]] in the [[An Lushan Rebellion]] against [[An Lushan]]. The Abbasids, or "Black Flags" as they were commonly called, were known in Tang dynasty chronicles as the ''hēiyī Dàshí'', "The Black-robed Tazi" ({{lang|zh|黑衣大食}}) ("Tazi" being a borrowing from Persian ''[[wikt:تازی|Tāzī]]'', the word for "Arab").{{refn|group=nb|Wade states "Tazi in Persian sources referred to a people in that land, but was later extended to cover Arab lands. The Persian term was adopted by Tang China (Dàshí :大食) to refer to the Arabs until the 12th century."<ref>{{harvnb|Wade|2012|p=138}}</ref>}} Later, Caliph [[Harun al-Rashid]] sent embassies to the Chinese [[Tang dynasty]] and established good relations with them.<ref name="Dennis Bloodworth, Ching Ping Bloodworth 2004 214" /><ref>{{harvnb|Jenkins|1999|p=61}}</ref><ref>{{harvnb|Ghosh|1961|p=60}}</ref> After the war, these embassies remained in China<ref>{{harvnb|Chapuis|1995|p=92}}</ref><ref>{{harvnb|Kitagawa|1989|p=283}}</ref><ref>{{harvnb|Smith|Weng|1973|p=129}}</ref><ref>{{harvnb|Baker|1990|p=53}}</ref><ref>{{harvnb|Fitzgerald|1961|p=332}}</ref> with al-Rashid establishing an alliance with China.<ref name="Dennis Bloodworth, Ching Ping Bloodworth 2004 214">{{harvnb|Bloodworth|Bloodworth|2004|p=214}}</ref> Several embassies from the Abbasid Caliphs to the Chinese court have been recorded in the ''[[Old Book of Tang]]'', the most important being those of al-Saffah, al-Mansur, and Harun al-Rashid.

[[File:Baghdad 150 to 300 AH.png|thumb|upright=1.2|Plan of [[Round city of Baghdad|Baghdad]] between 767 and 912 CE, according to [[William Muir]]]]
In 762, al-Mansur suppressed [[Alid revolt of 762–763|a rebellion]] in the [[Hejaz]] led by [[Al-Nafs al-Zakiyyah|al-Nafs al-Zakiyya]], a descendant from [[Ali ibn Abi Talib]], whose challenge to the Abbasid claim to leadership was based on his Alid lineage and thus presented a serious political threat. He was defeated by an Abbasid army led by [[Isa ibn Musa]].{{sfn|El-Hibri|2021|pp=51-55}} It was after this victory, in 762, that al-Mansur finally established a proper Abbasid capital, [[Round city of Baghdad|Baghdad]] – officially called ''Madinat al-Salam'' ('City of Peace') – located on the [[Tigris River]], near the former ancient capital city of [[Ctesiphon]].{{sfn|El-Hibri|2021|pp=55-57}} Prior to this, he had continued to consider multiple sites for a capital, including al-Hashimiyya, which he used as a capital for a while,{{sfn|El-Hibri|2021|pp=48-49}} and [[Weh Antiok Khosrow|al-Rumiyya]] (near the ruins of Ctesiphon), which he used for a few months.<ref>{{Cite book |last=Le Strange |first=Guy |chapter-url=https://archive.org/details/dli.ministry.15611/page/39/mode/2up |title=Journal of the Royal Asiatic Society of Great Britain and Ireland for 1895 |publisher=The Society |year=1895 |location=London |pages=40 |language=en |chapter=Description of Mesopotamia and Baghdad, written about the year 900 A.D. by Ibn Serapion}}</ref> Various other sites in the region also appear to have served as "capitals" under either al-Saffah or al-Mansur prior to the founding of Baghdad.<ref name="Hashimiyya" />

Al-Mansur centralised the judicial administration and, later, Harun al-Rashid established the institution of Chief Qadi to oversee it.<ref>{{Cite book|last=Tillier|first=Mathieu|title=Les cadis d'Iraq et l'État Abbasside (132/750–334/945) |doi=10.4000/books.ifpo.673|publisher=Presses de l’Ifpo|year=2009|isbn=978-2-35159-028-7|location=Damascus}}</ref> The Umayyad empire was mostly Arab; however, the Abbasids progressively became made up of more and more converted Muslims in which the Arabs were only one of many ethnicities.{{sfn|Bobrick|2012|p=40}} The Abbasids had depended heavily on the support of Persians<ref name=":11" /> in their overthrow of the Umayyads. Al-Mansur welcomed non-Arab Muslims to his court. While this helped integrate Arab and Persian cultures, it alienated many of their Arab supporters, particularly the [[Khorasani Arabs|Khurasani Arabs]] who had supported them in their battles against the Umayyads.{{Citation needed|date=June 2024}}

===Golden age (775–861)===
The Abbasid leadership had to work hard in the last half of the 8th century (750–800) under several competent caliphs and their [[Vizier (Abbasid Caliphate)|viziers]] to usher in the administrative changes needed to keep order of the political challenges created by the far-flung nature of the empire, and the limited communication across it.<ref name="Brauer">{{harvnb|Brauer|1995}}</ref> It was also during this early period of the dynasty, in particular during the rule of al-Mansur, Harun al-Rashid, and [[al-Ma'mun]], that its reputation and power were created.<ref name=":11" />

[[File:Decorated niche, 750-825 CE, Afrasiab, Samarkand.jpg|thumb|Decorated niche from the Abbasid mosque of [[Afrasiyab (Samarkand)|Afrasiab]], [[Samarkand]] in [[Sogdia]], 750–825 CE.<ref>{{cite book |last1=Allegranzi |first1=Viola |last2=Aube |first2=Sandra|title=Splendeurs des oasis d'Ouzbékistan |date=2022 |publisher=Louvre Editions |location=Paris |isbn=978-8412527858 |page=181}}</ref>]]
The position of ''wazir'' (vizier) developed in this period. It was initially akin to a secretary, but under the tenure of the [[Barmakids]], an Iranian family close to the Abbasids, the position became powerful and Harun al-Rashid delegated state affairs to them for many years.<ref>{{Encyclopaedia of Islam, Second Edition|volume=11|page=185|first=Muhammad Qasim|last=Zaman|article=Wazīr}}</ref> This resulted in a more ceremonial role for many Abbasid caliphs relative to their time under the Umayyads; the viziers began to exert greater influence, and the role of the caliph's aristocracy was slowly replaced by a Barmakid bureaucracy.<ref name="AHGC" /> At the western end of the empire, Harun al-Rashid agreed to grant the province of [[Ifriqiya]] (centered in present-day Tunisia) as a hereditary emirate to [[Ibrahim ibn al-Aghlab]], who founded the [[Aghlabid dynasty]] there.{{sfn|El-Hibri|2021|p=88}}

Under Harun al-Rashid's reign ({{Reign|786|809}}), the Abbasid Empire reached its peak.<ref>{{cite book | url=https://books.google.com/books?id=RIB5qT9sGnwC&dq=harun+al-rashid+released+umayyads&pg=PA191 | title=Historical Dictionary of Iraq | isbn=978-0810865686 | last1=Ghareeb | first1=Edmund A. | last2=Dougherty | first2=Beth | date=2004 | publisher=Scarecrow Press }}</ref><ref name="mag">{{harvnb|Magnusson|Goring|1990|p=2}}</ref> His father, [[al-Mahdi]] ({{Reign|775|785}}), [[Abbasid invasion of Asia Minor (782)|restarted the fighting]] with the [[Byzantine Empire|Byzantines]], and his sons continued the conflict until [[Irene of Athens|Empress Irene]] pushed for peace.{{sfn|Dupuy|Dupuy|1986|p=233}} After several years of peace, [[Nikephoros I]] broke the treaty, then fended off multiple incursions during the first decade of the 9th century. These Abbasid attacks pushed into the [[Taurus Mountains]], culminating with a victory at the [[Battle of Krasos]] and the [[Abbasid invasion of Asia Minor (806)|massive invasion of 806]], led by al-Rashid himself.<ref name="DD1">{{harvnb|Dupuy|Dupuy|1986|p=265}}</ref> Harun al-Rashid's navy also proved successful, taking [[Cyprus]]. Al-Rashid then focused on the rebellion of [[Rafi ibn al-Layth]] in Khurasan and died while there.<ref name="DD1" />

[[File:Harun al-Rashid receives envoys from Charlemagne.jpg|thumb|[[Harun al-Rashid]] ([[reign|r.]] 786–809) receiving a delegation sent by [[Charlemagne]] at his court in Baghdad. Painting by Julius Köckert (1827–1918), dated 1864. Oil on canvas.]]
Domestically, al-Rashid pursued policies similar to those of his father al-Mahdi. He released many of the Umayyads and Alids his brother [[al-Hadi]] ({{Reign|785|786}}) had imprisoned and declared amnesty for all political groups of the [[Quraysh]].<ref>{{cite book | url=https://books.google.com/books?id=RIB5qT9sGnwC&dq=harun+al-rashid+released+umayyads&pg=PA191 | title=Historical Dictionary of Iraq | isbn=978-0810865686 | last1=Ghareeb | first1=Edmund A. | last2=Dougherty | first2=Beth | year=2004 | publisher=Scarecrow Press }}</ref> While Baghdad remained the official capital, al-Rashid chose to reside in [[Raqqa]] from 796 until the end of his reign.{{sfn|El-Hibri|2021|p=88}}{{refn|group=nb|This city had previously been the residence of his father, al-Mahdi, whom al-Mansur had appointed its governor in 771. Al-Mahdi constructed a new city for himself, al-Rafiqa, next to Raqqa, and the two towns came to form a single urban agglomeration over time.{{sfn|El-Hibri|2021|p=69}}}} In 802, he established an unusual succession plan which decreed that his son [[al-Amin]] would inherit the title of Caliph and have control of Iraq and the western empire while his other son [[al-Ma'mun]] would rule Khurasan and most eastern parts of the empire.{{Sfn|Kennedy|2016|pp=124–127}} In 803, he turned on and imprisoned or killed most of the Barmakids, who had wielded administrative power on his behalf.<ref>{{harvnb|Meisami|1999}}</ref>{{sfn|El-Hibri|2021|pp=84-88}} The reasons for this sudden and ruthless move remain unclear and have been the subject of much discussion by contemporary writers and later historians.{{sfn|El-Hibri|2021|pp=84-88}}{{Sfn|Kennedy|2016|pp=127–129}} 

[[File:Abbasid Dinar - Al Amin - 195 AH (811 AD).jpg|thumb|[[Gold dinar]] minted during the reign of [[al-Amin]] (809–813)]]
Al-Rashid's decision to split the succession proved to be damaging to the longevity of the empire.<ref>{{Cite book |last=Frye |first=Richard |url=https://books.google.com/books?id=hvx9jq_2L3EC&pg=PA86 |title=The Cambridge History of Iran. Volume 4: The Period from the Arab Invasion to the Saljuqs |date=26 June 1975 |publisher=Cambridge University Press |isbn=9781139054966 |pages=86}}</ref> After his death in 809, his succession pact eventually collapsed and the empire was split by a [[Fourth Fitna|civil war]] between al-Amin in Iraq and al-Ma'mun in Khurasan. This ended with a successful [[Siege of Baghdad (812–813)|siege of Baghdad]] by al-Ma'mun's forces.{{Sfn|Kennedy|2016|p=|pp=135–148}} When the city fell in 813, al-Amin was captured and executed on the orders of al-Ma'mun's general, [[Tahir ibn Husayn]]. This marked the first time that an Abbasid ruler was publicly executed and it irrevocably damaged the prestige of the caliphate.{{Sfn|Kennedy|2016|p=148}}

Al-Ma'mun became caliph and ruled until his death in 833. He initially ruled the empire from his established base in Merv, Khurasan, where his main support was found, but this prolonged the discontent and instability in Iraq and triggered further fighting in the years following his victory.{{Sfn|Kennedy|2016|pp=151–162}}{{Sfn|El-Hibri|2021|p=|pp=108–109}} In 817, he officially declared an Alid, [[Ali al-Rida|'Ali al-Rida]], as his heir, instead of an Abbasid family member, perhaps hoping to promote Muslim unity, but the move backfired.{{Sfn|Kennedy|2016|pp=157–161}}{{Sfn|El-Hibri|2021|p=109}} Eventually, he was compelled to step back from these policies and move his court to Baghdad, where he arrived in August 819.{{Sfn|Kennedy|2016|pp=161–162}} After this, the rest of his reign was relatively peaceful. Exceptions included a rebellion in [[Iranian Azerbaijan|Azerbaijan]] by the [[Khurramites]], supported by the Byzantines, which continued until 837.<ref name="DD1" /> He also repulsed a Byzantine attack on Syria around 829, followed by counter-attacks into Anatolia, and suppressed a rebellion in Egypt in 832.<ref name="DD1" /> 

The later years of al-Ma'mun's reign are known for his intellectual interests and patronage. The so-called [[Graeco-Arabic translation movement|"translation movement"]] — the state-sponsored translation of scientific and literary works of antiquity into Arabic — that had begun under his predecessors was pushed even further during this time and al-Ma'mun shifted its focus to [[Ancient Greece|ancient Greek]] works of [[Science in classical antiquity|science]] and [[Ancient Greek philosophy|philosophy]].{{Sfn|El-Hibri|2021|p=|pp=117–122}} In matters of religion, his interest in philosophy spurred him to endorse [[Mu'tazilism]], the rationalist school of Islamic thought. Under its influence, he officially endorsed the doctrine of [[createdness of the Qur'an]] in 827. In 833, he went further and forcibly imposed it on the ''[[ulama]]'', the [[Sunni]] religious scholars.{{Sfn|El-Hibri|2021|p=|pp=122–123}} This controversial policy, known as the ''[[Mihna]]'', was eventually abandoned in 848. Ultimately, it failed to convince the Sunni ''ulama'' and instead contributed to the emergence of the latter as a more cohesive social class whose views and interests did not always align with the caliph.{{Sfn|El-Hibri|2021|p=|pp=122–126}}

Following the civil war between al-Amin and al-Ma'mun, the traditional mainstay of the Abbasid army, the ''Khurasaniyya'' and ''[[Abna al-dawla|<nowiki/>'Abna al-dawla]]'', were no longer seen as reliable and the caliphs sought to recruit a new type of army whose loyalty could be better assured.{{Sfn|Kennedy|2001|p=118}} This process began under al-Ma'mun but it is his brother and successor, [[al-Mu'tasim]] ({{Reign|833|842}}), who is known for its more radical implementation. Soldiers were recruited from several new sources, but the most important, especially under al-Mu'tasim, were the group referred to by Arabic chronicles as "Turks" ({{Transliteration|ar|atrāk}}), who appear to have been mainly [[Turkic peoples|Turkic]] people from Central Asia.{{Sfn|Kennedy|2001|p=|pp=118–120}}{{Sfn|El-Hibri|2021|p=131}} Some modern scholars refer to them as [[Mamluks]], marking them as the antecedent of the later slave-soldiers known by that term, but their exact legal status has been a subject of scholarly debate.{{Sfn|Kennedy|2001|p=|pp=121–122}}{{Sfn|Kennedy|2004|p=157}}{{Sfn|El-Hibri|2021|p=131}} Many, perhaps the majority, were originally purchased or captured slaves,{{Sfn|Kennedy|2001|p=|pp=121–122}}{{Sfn|El-Hibri|2021|p=131}} but they were paid regular salaries and thus likely [[manumitted]].{{Sfn|Kennedy|2001|p=|pp=121–122}} In any case, these outsiders did not have political ties among the traditional elites and thus their loyalty was to the caliph alone.{{Sfn|Kennedy|2001|p=118}}

[[File:قصر البركة في سامراء.jpg|thumb|upright=1.2|Partly-reconstructed remains of a courtyard with circular pool in the ''Dār al-Khilāfa'', the caliph's palace, in [[Abbasid Samarra|Samarra]], begun in 836.<ref>{{Cite journal |last=Northedge |first=Alastair |date=1993 |title=An Interpretation of the Palace of the Caliph at Samarra (Dar al-Khilafa or Jawsaq al-Khaqani) |url=https://www.jstor.org/stable/4629446 |journal=Ars Orientalis |volume=23 |pages=143–170 |jstor=4629446 |issn=0571-1371}}</ref><ref>{{Cite book |last=Westbrook |first=Nigel |chapter-url=https://books.google.com/books?id=RwEtDwAAQBAJ&pg=PA140 |title=Byzantium, Its Neighbours and Its Cultures |publisher=Brill |year=2014 |isbn=978-90-04-34491-4 |editor-last=Dzino |editor-first=Danijel |pages=140 |language=en |chapter=Exchange of palatine architectural motifs between Byzantium, Persia and the Caliphate |editor-last2=Parry |editor-first2=Ken}}</ref>]]
These troops were likely the first [[standing army]] of the caliphate{{Sfn|El-Hibri|2021|p=132}} and provided the caliph with a strong base of military support.{{Sfn|Kennedy|2004|p=163}} However, the influx of new foreign troops into the capital created tensions with its inhabitants and with older elites. This was one of the main reasons why, in 836, al-Mu'tasim decided to found a new capital, [[Abbasid Samarra|Samarra]], on an open site to the north of Baghdad.{{Sfn|Kennedy|2004|p=163}}{{Sfn|El-Hibri|2021|p=132}} The new capital housed the caliph's army, allowed for the unhindered construction of massive new palaces, and became the focus of an even more elaborate courtly culture.{{Sfn|Kennedy|2004|pp=163–164}}{{Sfn|El-Hibri|2021|p=|pp=133–139}}

Al-Mu'tasim's reign marked the end of the strong caliphs. He strengthened his personal army with the Mamluks and promptly restarted the war with the Byzantines. Though his attempt to seize [[Constantinople]] failed when his fleet was destroyed by a storm, his military excursions were generally successful, culminating with a resounding victory in the [[Sack of Amorium]].<ref>{{harvnb|Dupuy|Dupuy|1986|pp=265–266}}</ref>

===Political fragmentation (861–945)===
{{further|Anarchy at Samarra}}From the ninth century onward, the Abbasids found they could no longer keep together a centralized polity from Baghdad, which had grown larger than that of [[Roman Empire|Rome]].<ref>{{Cite book |last=Wickham |first=Chris |url=https://books.google.com/books?id=yDiDfipV4AIC&pg=PT239 |title=The Inheritance of Rome: A History of Europe from 400 to 1000 |publisher=Penguin UK |year=2009 |isbn=978-0-14-190853-3 |language=en}}</ref> As mentioned, Harun al-Rashid had already granted the province of Ifriqiya to the Aghlabids, who ruled this region as an autonomous vassal state until its fall to the [[Fatimids]] in 909.<ref name=":7">{{Cite book |last=Bosworth |first=Clifford Edmund |title=The New Islamic Dynasties |publisher=Columbia University Press |year=1996 |isbn=978-0-231-10714-3 |pages=31–32 |language=en |chapter=The Aghlabids |chapter-url=https://books.google.com/books?id=maQxEAAAQBAJ&pg=PA31}}</ref> In al-Ma'mun's reign, Tahir ibn Husayn (al-Ma'mun's general in the civil war) was appointed viceroy of Iran and most of the eastern regions of the empire from 821 onward. His descendants, the [[Tahirids]], continued to govern in this position with significant autonomy until 873, although they remained loyal to the caliph and used only the title of ''[[amir]]''. From their capital at [[Nishapur]], they were important patrons of Arabic literature and Sunni religious scholarship, in addition to making major improvements to agriculture.{{Sfn|El-Hibri|2021|pp=147–148, 292}} In [[Transoxiana]], the Persian [[Samanids]] of [[Bukhara]] and [[Samarkand]] ruled as local governors, initially under the Tahirids. They oversaw the development of the region's cities into major trade centers, profiting from long-distance trade between China, Central Asia, Eastern Europe, and the Middle East.{{Sfn|El-Hibri|2021|p=|pp=148–149}}

[[File:صوره في اجواء مطريه للمأذنه الملويه في سامراء العراق.jpg|thumb|The walls and spiral [[minaret]] of the [[Great Mosque of Samarra]], built from 848 to 852 CE in the Abbasid capital of [[Samarra]]<ref name=":3">{{Cite book |last=Northedge |first=Alastair E. |title=Encyclopaedia of Islam, Three |publisher=Brill |year=2012 |isbn=9789004161658 |editor-last=Fleet |editor-first=Kate |location= |pages= |chapter=ʿAbbāsid art and architecture |editor-last2=Krämer |editor-first2=Gudrun |editor-last3=Matringe |editor-first3=Denis |editor-last4=Nawas |editor-first4=John |editor-last5=Rowson |editor-first5=Everett}}</ref>]]
The reign of [[al-Mutawakkil]] ({{Reign|847|861}}) was characterized by the caliph's extravagant spending, his attempts to further consolidate power within the state, and his replacement of the ''Mihna'' policy with support for more orthodox Sunni scholars, in particular the [[Hanbali school]].{{Sfn|El-Hibri|2021|pp=141–142}} In 853, the Byzantines [[Sack of Damietta (853)|sacked Damietta]] in Egypt, and the caliph responded by sending troops into Anatolia, who sacked and marauded until they were [[Battle of Lalakaon|eventually annihilated]] in 863.<ref name="DD3">{{harvnb|Dupuy|Dupuy|1986|p=266}}</ref> 

Al-Mutawakkil's lifestyle and spending weakened his support among the military. In 861, he was murdered at a party by a group of Turkish soldiers.{{Sfn|El-Hibri|2021|pp=142–143}} This was the first time the Abbasid military intervened so directly and violently at court and it set a precedent for further coups.{{Sfn|El-Hibri|2021|p=143}} The following period, sometimes known as the "[[Anarchy at Samarra]]" (861–870), saw four different caliphs come and go. While they each attempted to reassert their authority, they were at the mercy of military and political factions. Tax collection lapsed and, along with al-Mutawakkil's previous spending, this left the state short on funds, which exacerbated the infighting.{{Sfn|Kennedy|2004|pp=169–170}} In 865, the Turkish soldiers of Samarra even [[Abbasid civil war (865–866)|besieged Baghdad]] to overthrow the caliph [[al-Musta'in]] and, when the city fell the following year, they replaced him with [[al-Mu'tazz]].{{Sfn|Kennedy|2004|pp=171–172}} The latter was overthrown by the same faction in 869 and replaced by [[al-Muhtadi]], who was similarly overthrown in 870. Al-Muhtadi was succeeded by [[al-Mu'tamid]], who was finally able to restore some order, in large part thanks to the help of his brother [[al-Muwaffaq]], who kept the military under control and ran most government affairs.{{Sfn|Kennedy|2004|pp=172–174}}{{Sfn|El-Hibri|2021|pp=146–147}} The restoration was hampered by the [[Zanj Rebellion|Zanj rebellion]], which erupted in 869 and threatened the center of Abbasid control in Iraq. This major threat was not brought under control until a determined campaign was launched in 879.{{Sfn|Kennedy|2004|pp=177–179}}

[[File:Abbasid Caliphate 891-892.png|thumb|upright=1.3|Map of the fragmented Abbasid empire {{circa|892}}, with areas still under direct control of the Abbasid central government (dark green) and under autonomous rulers adhering to nominal Abbasid suzerainty (light green)]]
By the 870s, Egypt became autonomous under [[Ahmad ibn Tulun]] and his [[Tulunid]] successors, though they continued to acknowledge the caliph and generally sent tribute to Baghdad. For a time, they even controlled Syria and parts of the Jazira ([[Upper Mesopotamia]]). In 882, the caliph al-Mu'tamid even tried (but failed) to move his residence to Egypt at Ibn Tulun's invitation.{{Sfn|Kennedy|2004|pp=174, 176–177}} 

In the east, the [[Saffarids]] were former soldiers in the Abbasid army who were stationed in [[Sistan]] and remained there as local strongmen. From 854 onward, they began to challenge the Tahirids and in 873 they captured Nishapur, ending Tahirid rule. They marched on Baghdad in 876 but [[Battle of Dayr al-Aqul|were defeated]] by al-Muwaffaq. The two sides were forced to come to terms and the Abbasids allowed the Saffarids to rule over Sistan, [[Fars province|Fars]], [[Kerman province|Kirman]], and [[Khurasan]].{{Sfn|El-Hibri|2021|pp=151–152}}{{Sfn|Kennedy|2004|pp=175–176}} 

In 898, al-Mu'tadid set the Saffarids and Samanids against each other but the latter came out triumphant in battle and were able to expand their control to Khurasan, while the Saffarids remained further south. The Samanids never threatened the Abbasids in Iraq, but they were also not as close to the caliphs as their Tahirid predecessors and in practice they were almost entirely independent of Baghdad.{{Sfn|Kennedy|2004|p=183}} They became even greater patrons of religion and the arts than the Tahirids, still maintaining orthodox Sunni ideology but differing in their promotion of the [[Persian language]].{{Sfn|El-Hibri|2021|pp=149–150}}

There was a brief Abbasid political and military revival at the end of the 9th century, especially under the policies of caliph [[al-Mu'tadid]] ({{Reign|892|902}}) and [[al-Muktafi]] ({{Reign|902|908}}).{{Sfn|Kennedy|2004|pp=179–185}} Under al-Mu'tadid, the capital was moved from Samarra back to Baghdad.{{Sfn|Kennedy|2004|p=180}} Incursions by the [[Qarmatians]] and allied Bedouin tribes posed a serious threat from 899 onwards, but the Abbasid army, led by [[Muhammad ibn Sulayman al-Katib|Muhammad ibn Sulayman]], won a reprieve against them in 904 and 907.{{Sfn|Kennedy|2004|pp=183–185}} In 905, the same general invaded Egypt and overthrew the weakened Tulunids, re-establishing Abbasid control to the west.{{Sfn|Kennedy|2004|pp=184–185}} By the time caliph al-Muktafi died in 908, the Abbasid revival was at its peak and a strong centralized state was in place again.{{Sfn|Kennedy|2004|p=185}} 

After his death, however, the state became dominated by feuding bureaucrats. Under [[al-Muqtadir]] ({{Reign|908|932}}), the Abbasid court continued to project power and wealth publicly but the politics and financial policies of the time compromised the caliphate's sustainability in the long-term. It was in this period that the practice of giving out [[iqta|''iqta'']]s ([[fief]]s in the form of tax farms) as favours began, which had the effect of reducing the caliphate's own tax revenues.{{Sfn|El-Hibri|2021|pp=163–168}}

In 909, North Africa was lost to the [[Fatimid dynasty]], an [[Isma'ilism|Isma'ili]] Shia sect tracing its roots to Muhammad's daughter [[Fatima]]. The Fatimids took control of Ifriqiya from the Aghlabids and eventually [[Fatimid conquest of Egypt|conquered Egypt]] in 969, where they established their capital, [[Cairo]], near [[Fustat]].{{Sfn|Kennedy|2004|p=|pp=313–317}}{{Sfn|Naylor|2015|pp=72–73, 79}} By the end of the century, they were one of the main political and ideological challenges to Sunni Islam and the Abbasids, contesting the Abbasids for the titular authority of the Islamic [[ummah|''ummah'']].{{Sfn|Naylor|2015|p=80}}{{Sfn|Daftary|Jiwa|2017|p=|pp=1–2}}{{Sfn|El-Hibri|2021|pp=195–196}} The challenge of the Fatimid Caliphate only ended with their downfall in the 12th century.{{Sfn|Daftary|Jiwa|2017|p=4}}

Under the caliph [[al-Radi]] ({{Reign|934|941}}), Baghdad's authority declined further as local governors refused to send payments to the capital. The [[Ikhshidids]] ruled Egypt and Syria autonomously prior to the Fatimid takeover. Even in Iraq, many governors refused to obey and the caliph was unable to send armies against them.{{Sfn|Kennedy|2004|pp=194–195}} Al-Radi was forced to invite the governor of [[Wasit]], [[Muhammad ibn Ra'iq]], to take over the administration under the newly-created position of ''[[amir al-umara]]'' ("Commander of Commanders").{{Sfn|Kennedy|2004|pp=194–195}} Ibn Ra'iq disbanded the salaried army of the caliph and reduced much of the government's bureaucratic infrastructure, including the traditional vizierate, thus removing much of the Abbasid state's basis for power. He was overthrown in 938 and the following years were bogged down in political turmoil.{{Sfn|Kennedy|2004|pp=195–196}}

[[Al-Mustakfi]] had a short reign from 944 to 946, and it was during this period that the Persian faction known as the [[Buyids]] from [[Daylam]] swept into power and assumed control over the bureaucracy in Baghdad. According to the history of [[Miskawayh]], they began distributing ''iqta''s to their supporters. This period of localized secular control was to last nearly 100 years.<ref name=":11" /><ref>{{Cite journal |last=Michele |first=Campopiano |date=2012 |title=State, Land Tax and Agriculture in Iraq from the Arab Conquest to the Crisis of the Abbasid Caliphate (Seventh-Tenth Centuries) |url=https://www.academia.edu/12137429 |url-status=live |journal=Studia Islamica |volume=107 |issue=1 |pages=1–37 |archive-url=https://web.archive.org/web/20180913114643/http://www.academia.edu/12137429/_State_Land_Tax_and_Agriculture_in_Iraq_from_the_Arab_Conquest_to_the_Crisis_of_the_Abbasid_Caliphate_Seventh-Tenth_Centuries_in_Studia_Islamica_3_2012_35-80 |archive-date=13 September 2018 |access-date=19 October 2015 |via=Academia.edu}}</ref>

Outside Iraq, all the autonomous provinces slowly took on the characteristic of de facto states with hereditary rulers, armies, and revenues and operated under only nominal caliph suzerainty, which may not necessarily be reflected by any contribution to the treasury, such as the [[Soomro]] emirs that had gained control of [[Sindh]] and ruled the entire province from their capital of [[Mansura, Sindh|Mansura]].<ref name="Brauer" /> [[Mahmud of Ghazni]] took the title of [[sultan]], as opposed to the ''amir'' that had been in more common usage, signifying the [[Ghaznavids|Ghaznavid Empire]]'s independence from caliphal authority, despite Mahmud's ostentatious displays of Sunni orthodoxy and ritual submission to the caliph. In the 11th century, the loss of respect for the caliphs continued, as some Islamic rulers no longer mentioned the caliph's name in the Friday [[khutba|''khutba'']], or struck it off their coinage.<ref name="Brauer" />

===Buyid and Seljuq control (945–1118)===
{{Further|Buyid dynasty|Seljuk Empire}}
{{More citations needed|section|date=February 2025}}
[[File:Buyids within the Middle East, ca. 970.png|thumb|upright=1.3|The Middle East {{Circa|970}}, after the Abbasids came under the control of the [[Buyid dynasty]]]]
Despite the power of the Buyid amirs, the Abbasids retained a highly ritualized court in Baghdad, as described by the Buyid bureaucrat [[Hilal al-Sabi']], and they retained a certain influence over Baghdad as well as religious life. As Buyid power waned with the rule of [[Baha' al-Daula]], the caliphate was able to regain some measure of strength. The caliph [[al-Qadir]], for example, led the ideological struggle against the Shia with writings such as the ''[[Baghdad Manifesto]]''. The caliphs kept order in Baghdad itself, attempting to prevent the outbreak of [[fitna (word)|''fitna''s]] in the capital, often contending with the ''[[ayyarun]]''.

With the Buyid dynasty on the wane, a vacuum was created that was eventually filled by the dynasty of [[Oghuz Turks]] known as the [[Seljuqs]]. By 1055, the Seljuqs had wrested control from the Buyids and Abbasids, and took temporal power.<ref name=":11" /> When the amir and former slave [[Basasiri]] took up the Shia Fatimid banner in Baghdad in 1056–57, the caliph [[Al-Qa'im (Abbasid caliph at Baghdad)|al-Qa'im]] was unable to defeat him without outside help. [[Toghril Beg]], the Seljuq sultan, restored Baghdad to Sunni rule and took Iraq for his dynasty.

Once again, the Abbasids were forced to deal with a military power that they could not match, though the Abbasid caliph remained the titular head of the Islamic community. The succeeding sultans [[Alp Arslan]] and [[Malikshah]], as well as their vizier [[Nizam al-Mulk]], took up residence in Persia, but held power over the Abbasids in Baghdad. When the dynasty began to weaken in the 12th century, the Abbasids gained greater independence once again.

===Revival of caliphal state (1118–1258)===
[[File:Map of the Abbasid Caliphate in 1180 CE.png|thumb|Approximate territory controlled by the Abbasids circa 1180, after gaining independence from the Seljuks<ref>{{Cite book |last1=Fisher |first1=William Bayne |url=https://books.google.com/books?id=16yHq5v3QZAC&pg=PA188 |title=The Cambridge History of Iran |last2=Boyle |first2=J. A. |publisher=Cambridge University Press |year=1968 |isbn=978-0-521-06936-6 |pages=188 |language=en}}</ref>]]
Caliph [[al-Mustarshid]] ({{Reign|1118|1135}}) was the first caliph to build an army and to lead it in battle since the 10th century.{{Sfn|Peacock|2015|p=147}} He recruited Kurdish and Arab Bedouin tribes and re-fortified Baghdad. His first concern was not the Seljuks but the [[Banu Mazyad|Mazyadids]] of [[Hilla]] in central Iraq, whom he met in battle in 1123. His bid for independence was ultimately unsuccessful, as he was defeated by a Seljuk army in 1135 and assassinated soon after.{{Sfn|Peacock|2015|pp=147–150}} 

Under [[al-Muqtafi]] ({{Reign|1136|1160}}), a new caliphal state began to emerge with the help of his vizier [[Awn ad-Din ibn Hubayra|Ibn Hubayra]].{{Sfn|Peacock|2015|pp=151–153}} Ibn Hubayra concentrated on reasserting authority in Iraq while the Seljuk Empire deteriorated. The Abbasids successfully defended Baghdad against the Seljuqs in the [[siege of Baghdad (1157)|siege of 1157]] and then conquered their Mazyadid enemies in Hilla in 1162.{{Sfn|Peacock|2015|pp=151–153}} By the end of al-Muqtafi's reign, Baghdad controlled a state stretching from [[Basra]] in the south to the edges of [[Mosul]] in the north.{{Sfn|El-Hibri|2021|p=233}} After over two hundred years of Abbasid subjection to foreign dynasties, Caliph [[al-Mustanjid]] ({{Reign|1160|1170}}) formally declared independence from the Seljuk sultans in 1165, when he dropped their names from Abbasid coinage.{{Sfn|Peacock|2015|p=153}} Initially, the caliphs were still vulnerable to the power of the viziers,{{Sfn|Peacock|2015|p=153}} but [[al-Mustadi]] ({{Reign|1170|1180}}) was able to further rally some support from the Baghdad public as well as symbolic support abroad from the [[Ayyubid dynasty|Ayyubid]] sultan [[Saladin]] and the [[Sultanate of Rum|Rum Seljuk]] sultan [[Kilij Arslan II]].{{Sfn|El-Hibri|2021|pp=228–230}}
[[File:Talisman Gate in Baghdad.jpg|thumb|Carving on [[Bab al-Talsim]], a Baghdad gate built by [[al-Nasir]] in 1221 (destroyed in 1917), possibly depicting the caliph wrestling dragons.{{Sfn|Bloom|Blair|2009|loc=Architecture; X. Decoration|p=197}}]]
The long reign of Caliph [[al-Nasir]] ({{Reign|1180|1225}}) marked a definitive shift in late Abbasid power. He reinvigorated public displays of caliphal prestige, removed officials who were too powerful, engaged in diplomacy with regions beyond Iraq, and extended his control over former Seljuk territories in western Iran — including [[Isfahan]], [[Hamadan]], [[Qazvin]] and [[Zanjan, Iran|Zanjan]].{{Sfn|El-Hibri|2021|pp=234–235}} He sought to build up his influence among Muslim rulers abroad largely through the [[Sufi]]-inspired [[futuwwa|''futuwwa'']] brotherhood that he headed.{{Sfn|El-Hibri|2021|pp=238–239}} Under caliph [[Al-Mustansir I|al-Mustansir]] ({{Reign|1226|1242}}), the Abbasid state achieved significant stability and many of the same policies continued.{{Sfn|El-Hibri|2021|pp=246–249}} He built the [[Mustansiriyya Madrasa]], inaugurated in 1234, the first madrasa to teach all four Sunni [[Madhhab|''maddhab''s]] (schools of [[Fiqh|jurisprudence]]) and the first madrasa commissioned by an Abbasid caliph.{{Sfn|El-Hibri|2021|pp=251–254}}

===Mongol invasion and end===
{{Main|Siege of Baghdad|Mongol invasions of the Levant}}In 1206, [[Genghis Khan]] established a powerful dynasty among the [[Mongols]] of Central Asia. During the 13th century, this [[Mongol Empire]] conquered most of the Eurasian land mass, including both China in the east and much of the old Islamic caliphate and the [[Kievan Rus']] in the west. In 1252, [[Hulagu Khan]], a grandson of Genghis Khan and brother of the new Mongol ruler, [[Möngke Khan]], was placed in charge of a new western campaign to the Middle East that would culminate in the [[Siege of Baghdad|conquest of Baghdad]] in 1258.{{Sfn|Jackson|2017|p=|pp=125–128}}

In the years leading up the Mongol invasion, Baghdad's strength was sapped by political rivalries, sectarian tensions between Sunnis and Shias, and damaging floods.{{Sfn|El-Hibri|2021|p=|pp=259–260}} In 1257, after [[Mongol campaign against the Nizaris|destroying the Assassins]] in Iran, Hulagu wrote to the Abbasid caliph, [[al-Musta'sim]], demanding his submission. The caliph refused, with Hulagu's status as a non-Muslim (unlike the earlier Buyids and Seljuks) likely a factor.{{Sfn|El-Hibri|2021|p=|pp=263–264}} There followed months of diplomacy, during which the Mongols may have been informed of Baghdad's weakness by correspondence with the caliph's vizier, [[Muhammad ibn al-Alqami|Ibn al-Alqami]], a Shia who was later accused of colluding with them.{{Sfn|El-Hibri|2021|p=|pp=263–265, 268}}<ref name=":10">{{Cite book |last=Lane |first=George |url=https://books.google.com/books?id=FlCBAgAAQBAJ&pg=PA29 |title=Early Mongol Rule in Thirteenth-Century Iran: A Persian Renaissance |publisher=Routledge |year=2003 |isbn=978-1-134-43103-8 |pages=29–35 |language=en}}</ref><ref>{{Cite book |last=Osman |first=Khalil |url=https://books.google.com/books?id=jhPEBAAAQBAJ&dq=alqami+1258&pg=PA64 |title=Sectarianism in Iraq: The Making of State and Nation Since 1920 |publisher=Routledge |year=2014 |isbn=978-1-317-67487-0 |pages=64 |language=en}}</ref>

[[File:DiezAlbumsFallOfBaghdad a.jpg|thumb|upright|[[Siege of Baghdad]] by the Mongols led by [[Hulagu Khan]] in 1258, as illustrated in a copy of the 14th-century ''[[Jami' al-tawarikh]]'']]
The Mongols began their siege of the city on 29 January 1258. On 10 February, al-Musta'sim agreed to meet with Hulagu, who demanded that the caliph order the defenders to stand down and come out of the city in exchange for mercy. The caliph complied, but the Mongols slaughtered the population and then began the sack of the city on 13 February.{{Sfn|El-Hibri|2021|p=|pp=266–267}} Contemporary accounts describe destruction, looting, rape, and killing on a massive scale over many days, with hundreds of thousands killed and the city reduced to near-empty ruins,{{Sfn|Marozzi|2014|pp=142–148}} though some, like the Christian and Shia communities, were spared.{{Sfn|El-Hibri|2021|p=268}}<ref name=":10" /> The Mongols feared rumours that a supernatural disaster would strike if the blood of al-Musta'sim, a direct descendant of Muhammad's uncle and part of a dynasty that had reigned for five centuries, was spilled. As a precaution and in accordance with a Mongol taboo against spilling royal blood, Hulagu had al-Musta'sim wrapped in a carpet and trampled to death by horses on 20 February 1258.<ref name=":9" />{{Sfn|El-Hibri|2021|p=|pp=267–268}}{{Sfn|Jackson|2017|p=|pp=128–129}}<ref>{{Cite book |last=DeVries |first=Kelly |chapter-url=https://books.google.com/books?id=tQcGDAAAQBAJ&pg=PA208 |title=Crusading and Warfare in the Middle Ages: Realities and Representations. Essays in Honour of John France |publisher=Routledge |year=2016 |isbn=978-1-317-15676-5 |editor-last=John |editor-first=Simon |pages=208–209 |language=en |chapter=Meet the Mongols: Dealing with Mamluk Victory and Mongol Defeat in the Middle East in 1260 |editor-last2=Morton |editor-first2=Nicholas}}</ref> The caliph's immediate family was also executed, with the lone exceptions of his youngest son who was sent to Mongolia and a daughter who became a slave in the [[harem]] of Hulagu.<ref name=":9">{{harvnb|Frazier|2005}}</ref>

The fall of Baghdad marked the effective end of the Abbasid Caliphate.{{Sfn|Bennison|2009|p=|pp=7, 47, 95, etc}}{{Sfn|Jackson|2017|p=|pp=128–129}} It made a deep impression on contemporary and later writers both inside and outside the Muslim world, some of whom created legendary stories about the last caliph's demise.{{Sfn|Jackson|2017|p=|pp=128–129}}{{Sfn|El-Hibri|2021|p=267}} It is also traditionally seen as the approximate end to the "classical age" or [[Islamic Golden Age|"golden age" of Islamic civilization]].<ref>{{harvnb|Cooper|Yue|2008|p=215}}</ref>{{Sfn|Bennison|2009|p=4}}<ref>{{Cite book |last1=Renima |first1=Ahmed |chapter-url=https://books.google.com/books?id=f9f7CwAAQBAJ&pg=PA25 |title=The State of Social Progress of Islamic Societies: Social, Economic, Political, and Ideological Challenges |last2=Tiliouine |first2=Habib |last3=Estes |first3=Richard J. |publisher=Springer |year=2016 |isbn=978-3-319-24774-8 |editor-last=Tiliouine |editor-first=Habib |location=Estes |pages=25 |language=en |chapter=The Islamic Golden Age: A Story of the Triumph of the Islamic Civilization |editor-last2=Estes |editor-first2=Richard J.}}</ref> The events brought profound geopolitical changes to the traditional lands of the Islamic caliphate, with Iraq, Iran, and most of the eastern lands falling under Mongol control while other Muslim rulers retained the lands to the west.{{Sfn|Bennison|2009|p=4}} Mongol expansion further west was eventually halted by the [[Mamluks of Egypt]] at the [[Battle of Ain Jalut]] in 1260, followed by the conflict between the [[Ilkhanids]] (Hulagu and his successors) and their [[Golden Horde]] rivals, which diverted Mongol attention.{{Sfn|El-Hibri|2021|p=269}} 

==== Abbasid caliphs in Cairo (1261–1517) ====
{{Main |Mamluk Sultanate}}
Prior to the Mongol invasion, the later Ayyubid sultans of Egypt had built up an army recruited from slaves, the [[Mamluks]]. During a political and military crisis in 1250, the Mamluks seized power and established what is now known as the Mamluk Sultanate.{{Sfn|El-Hibri|2021|pp=258–259, 270}} Following the devastation of Baghdad in 1258 and in an effort to secure political legitimacy for the new regime in Egypt, the Mamluk ruler [[Baybars]] invited a surviving member of the Abbasid family to establish himself in Cairo in 1260–1261. The new caliph was [[al-Mustansir II]], a brother of the former caliph al-Mustansir.<ref name=":5">{{Cite book |last=Bosworth |first=Clifford Edmund |author-link=Clifford Edmund Bosworth |chapter-url=https://books.google.com/books?id=maQxEAAAQBAJ&pg=PA6 |title=The New Islamic Dynasties: A Chronological and Genealogical Manual |publisher=Edinburgh University Press |year=1996 |isbn=9780748696482 |location= |pages=6–10 |language=en |chapter=The 'Abbasid Caliphs}}</ref>{{Sfn|El-Hibri|2021|p=270}} In 1262, he disappeared while leading a small army in an attempt to recapture Baghdad from the Mongols. Baybars subsequently replaced him with [[al-Hakim I]], another Abbasid family member who had just been proclaimed in [[Aleppo]].<ref name=":5" />{{Sfn|El-Hibri|2021|p=271}} 

Thereafter, the Abbasid caliphs in Cairo continued to exist as a strictly ceremonial but nonetheless important institution within the Mamluk Sultanate, conferring significant prestige on the Mamluks.<ref name=":5" />{{Sfn|El-Hibri|2021|p=272}} It continued to be relevant even to other Muslim rulers until the 14th century; for example, the [[Delhi Sultanate|sultans of Delhi]], the [[Muzaffarids (Iran)|Muzaffarid]] sultan [[Mubariz al-Din Muhammad|Muhammad]], the [[Jalayirid Sultanate|Jalayirid]] sultan [[Ahmad Jalayir|Ahmad]], and the [[Ottoman Empire|Ottoman]] sultan [[Bayezid I]] all sought diplomas of investiture from the caliph or declared nominal allegiance to him.{{Sfn|El-Hibri|2021|p=|pp=273–275}} Caliph [[Al-Musta'in (Mamluk Sultanate)|al-Musta'in]] even managed to reign as sultan in Cairo for a brief six months in 1412.{{Sfn|El-Hibri|2021|p=275}}

During the 15th century, however, the institution of the caliph declined in significance.{{Sfn|El-Hibri|2021|p=275}} The last Abbasid caliph in Cairo was [[al-Mutawakkil III]], who was in place when the Ottoman sultan Selim II [[Battle of Marj Dabiq|defeated the Mamluks]] in 1516 and [[Ottoman–Mamluk War (1516–1517)|conquered Egypt]] in 1517, ending the Mamluk Sultanate. Selim II met with al-Mutawakkil III in Aleppo in 1516, prior to marching into Egypt, and the caliph was then sent to the Ottoman capital of [[Constantinople]] (present-day [[Istanbul]]), ending the Abbasid caliphate definitively.<ref name=":5" />{{Sfn|El-Hibri|2021|p=|pp=275–276}} The idea of a "caliphate" subsequently became an ambiguous concept that was occasionally revisited by later Muslim rulers and intellectuals for political or religious reasons.{{Sfn|El-Hibri|2021|p=276}} The Ottoman sultans, who were thenceforth the most powerful Muslim rulers in western Asia and the Mediterranean, did not use the title of "caliph" at all before the mid-16th century and only did so vaguely and inconsistently afterwards.<ref name=":6">{{Cite book |last=Karateke |first=Hakan |chapter-url=https://books.google.com/books?id=JoZSEAAAQBAJ&pg=PA25 |title=Legitimizing the Order: The Ottoman Rhetoric of State Power |publisher=Brill |year=2005 |isbn=978-90-474-0764-5 |editor-last=Hakan |editor-first=Maurus |pages=25–26 |language=en |chapter=Legitimizing the Ottoman Sultanate: A Framework for Historical Analysis |editor-last2=Reinkowski |editor-first2=Maurus}}</ref> The claim that al-Mutawakkil III "transferred" the office of the caliph to the Ottoman sultan during their meeting in Aleppo is a legend that was elaborated in the 19th century and is not corroborated by contemporary accounts.<ref name=":5" /><ref name=":6" />