Abbasid Caliphate

The Abbasid Caliphate was a semi-religious political system of governance in Islam, in which a supreme leader called the caliph, meaning successor, ruled the empire. It was founded in 750 CE, with the overthrow of the Umayyad Caliphate.

The town and oasis of Marv in northern Khorasan, far from the bases of Omayyad power in Syria and from the garrison cities of Iraq, was the epicenter of ʿAbbasid propaganda, and it was from there that the victorious forces of Abū Moslem marched westward via Ray and Jebāl to the plains of Iraq and the defeat of the Omayyad forces. Al-Mansur commissioned the creation of a new capital in the Fertile Crescent near the Tigris River, Baghdad, a bustling metropolis that humbled all European cities of the time in every standard.

Harun al-Rashid became caliph in September 786 after the death of al-Hadi, which rumor attributed to al-Khayzuran because he had resisted her domination. The fabulous descriptions of Harun and his court in The Thousand and One Nights are idealized and romanticized, but they had a considerable basis in fact: untold wealth flowed into Baghdad since its foundation, and conspicuous consumption by the empire's leading men and their wives reached unprecedented levels in his reign.

The Khorasanian guards were eclipsed only when Moʿtaṣem expanded the recruitment of professional soldiers and slaves from the Turkish steppes and from North Africa.

Baghdad was in its prime about 800 CE during the reign of the caliph Harun al-Rashid, the city forming two vast semi-circles on the right and left banks of the Tigris, twelve miles in diameter. Its population, together with that of its suburbs, amounted to over two million. Although Baghdad remained an Arabic-speaking city, its metropolitan status and its geographical position meant that its population and urban environment contained considerable Persian elements.

Harun al-Rashid encouraged scholarship, and the first translations of Greek texts into Arabic, such as Euclid's Elements by al-Hajjaj, were made in his reign. The next caliph, al-Ma'mun, encouraged learning even more strongly and set up the House of Wisdom in Baghdad, which became the centre for both the work of translating and of research. Al-Khwarizmi and his colleagues the Banu Musa were scholars at the House of Wisdom, where they translated Greek scientific manuscripts and wrote on algebra, geometry and astronomy, and he worked under the patronage of al-Mamun, dedicating his treatises on algebra and on astronomy to him.

Thabit ibn Qurra, whose skills in languages were matched by great mathematical skills, translated and revised many of the important Greek works, at a time when patrons employed talented scientists to translate Greek texts into Arabic.

Harun al-Rashid, the fifth caliph of the dynasty, reigned from 786 to 809 and made Yahya the Barmakid his vizier, inheriting an empire that stretched from the western Mediterranean to India. The Barmak family traced its origin to the region of Balkh, where its ancestor Barmak served, according to early Muslim authors, as high priest of the Zoroastrian fire temple of Nowbahar; the name Nowbahar likely derives from the Buddhist Sanskrit nava-vihara, meaning "new monastery," and the eponym Barmak may come from the Sanskrit pramukha, "chief." Khalid b. Barmak was commissioned in 158/774 to suppress a revolt in Mosul and governed the city until al-Mansur's death a few months later, and under al-Mahdi he received Shammasiya as a fief, where he built residential quarters later known as Sowayqat Khalid.

Khalid's son Yahya rose first as an assistant to his father in governing Ray, then as tutor to the prince Harun, and then as secretary and treasurer to Harun during the latter's campaign against Byzantium; in 163/779, as deputy governor of Fars, he managed to abolish the taxes paid on trees, and Khalid died in 165/781-82 shortly after Harun returned from his campaign. The Barmakids were influential during the first Abbasid reigns and held the substance of power for seventeen years of Harun al-Rashid's reign, leaving after their sudden fall a semilegendary reputation as Maecenases and as furtherers of Persian domination within the state.

What passed between 183/799 and the caliph's pilgrimage in 186/802 to turn Harun against his viziers is not clear, but he ordered Ja'far killed in 187/803; Fadl and his brothers were arrested, Yahya was put under surveillance, and the property of all the Barmakids except Muhammad b. Among the reported causes of the reversal were his sense of being dominated by the family and his coveting of their wealth.

Harun divided the empire between his sons al-Amin and al-Ma'mun, an arrangement that later led to war between them after his death and contributed to the empire's disintegration; he died in March 809 at Tus in Iran.

Al-Ma'mun, caliph from 813 to 833, commanded the human and material resources of Persia from his governorate in Marv and defeated his brother al-Amin in 198/813, while the latter's cause was identified with the Arabs of Iraq and Syria. Al-Amin was besieged in Baghdad in April 812 and the city taken only in September 813; already declared deposed as caliph in Iraq and Arabia, he was killed while trying to surrender, contrary to al-Ma'mun's orders, in one of the most merciless civil wars known to the Islamic East.

Al-Ma'mun proved a judicious sovereign who kept his ministers under close control and did not appoint another all-powerful vizier; though he tried to maintain strict control over provincial governors, he had to allow a degree of autonomy to his former general Tahir as governor of Khurasan. His love of arts and learning surpassed even his father's, but his decision to rationalize his society in opposition to the basic beliefs of his Muslim population, including debate over whether the Quran could be rewritten or altered, led to his falling from the favour of many Islamic historians.

He encouraged the translation of Greek philosophical and scientific works, founded an academy called the House of Wisdom to which translators, most often Christians, were attached, and imported important manuscripts from Byzantium. Ahmad ibn Hanbal, founder of the Hanbali school of Islamic law, was to be sent under heavy guard before al-Ma'mun but was spared by the caliph's sudden death at Tarsus in 833; traditionalists called the episode the mihna, which showed that part of public opinion resisted the beliefs the caliph wished to impose.

Al-Kindi moved to Baghdad to complete his studies after beginning his education in Kufah, quickly achieved fame for his scholarship, and came to the attention of al-Ma'mun, who was at that time setting up the House of Wisdom in Baghdad; after al-Ma'mun's death al-Kindi continued to enjoy favour under al-Mu'tasim, who employed him to tutor his son Ahmad, but fared less well under the later caliphs al-Wathiq and al-Mutawakkil. Al-Kindi became known as the philosopher of the Arabs, the only notable philosopher of pure Arabian blood and the first in Islam, held unique among his contemporaries in knowledge of the totality of the ancient scientists, embracing logic, philosophy, geometry, mathematics, music and astrology.

The Graeco-Hellenistic heritage was carried into Islamic science by translators such as Hunain ibn Ishaq and Thabit ibn Qurrah, who worked from Syriac or Greek, with Greek authors rendered into Arabic in nearly every domain of knowledge.

Many of the ideas previously thought to have been brilliant new conceptions due to European mathematicians of the sixteenth, seventeenth and eighteenth centuries are now known to have been developed by Arabic or Islamic mathematicians around four centuries earlier. The mathematics studied today is in many respects closer in style to that of the Arabic or Islamic contribution than to that of the Greeks.

Samarra preserves two of the largest mosques, Al-Malwiya and Abu Dulaf, with the most unusual minarets and the largest palaces in the Islamic world, including the Caliphal Palace Qasr al-Khalifa; the carved stucco known as the Samarra style developed there spread to other parts of the Islamic world. In Samarra a new way of carving surfaces, the so-called beveled style, and a repetition of abstract geometric or pseudo-vegetal forms later known in the West as arabesque, were widely used as wall decoration and became popular in other media such as wood, metalwork, and pottery.

The Main Caliphal Palace at Samarra, known in Arabic as Dar al-Khilafa or Qasr al-Khalifa, served as the primary residence of al-Mu'tasim and several of his successors, with construction beginning circa 836/221 AH. Northedge interpreted the axially arranged buildings at the southern end of the Dar al-Khilafa as the Dar al-'Amma, halls of public audience where the court conducted its public ceremonies, while the northern enclosure served as the caliphs' private residence.

After al-Ma'mun, the Abbasids' immediate successors failed to live up to their responsibilities and let their private Turkish bodyguards extend their influence over the court, and Abbasid dominance was finally broken when al-Mutawakkil was assassinated in a court coup instigated by the Turks. With the domination in Baghdad of a series of Turkish commanders bearing the title of amīr-al-omarāʾ, and the installation of the Buyids in west and central Persia and then in Iraq, the ʿAbbasids' direct political power was restricted to the Sawad, the agricultural region around Baghdad, and they possessed no authority over Persia itself.

In 1258 the Mongols conquered the Abbasid Caliphate and sacked Baghdad, murdering the caliph; their advance into the heartland of Islam was halted at Ain Jalut in 1260 and Abbasid shadow caliphs were kept in Cairo by their Mamluk overlords until 1517 CE.

The caliphs were initially the sole sovereigns of the empire left behind by Muhammad and added vast territories of surrounding rival empires to it. Under the ʿAbbasids the Khorasanian guards of the caliphs held the dominant place in the army, while Persian officials and secretaries, as well as military commanders, played an increased role in shaping and guiding the state apparatus, and prominent Persian families filled the vizierate and the chief secretarial posts for long periods. The chief executives whom the first ʿAbbasids appointed naturally tended to come from the ranks of the adherents to their cause in the revolutionary period, such as the Barmakī family, or else from socially obscure personal freedmen of the caliphs such as Manṣūr's mawlā Rabīʿ b. Yūnos, and it is in this period that the specific office of the vizierate develops under the explicit name vezāra.

At its height the caliphate extended from Tunisia to Central Asia, and Samarra Archaeological City preserves the site of a powerful Islamic capital that ruled the provinces of the Abbasid Empire across that same span, lying on both sides of the River Tigris 130 km north of Baghdad and running 41. 5 km from north to south. Under the Abbasids the first three centuries of their rule were a golden age, with Baghdad and Samarra functioning as the cultural and commercial capitals of the Islamic world.

• 750 CE
  Founding of the caliphate
  The Abbasid Caliphate is established with the overthrow of the Umayyad Caliphate.
• 750–754
  Reign of Abu Abbas as-Saffah
  Abu Abbas as-Saffah rules as caliph.
• 751 CE
  Battle of Talas
  The Battle of Talas is fought.
• 762
  Founding of Baghdad
  Baghdad, officially Madinat al-Salam, the City of Peace, is founded by the second Abbasid caliph, Abu Ja'far al-Mansur, as his official capital. ^{6BAGHDAD i. The Iranian Connection: Before the Mongol Invasion · Encyclopaedia Iranica (Columbia University) ↗}
• 786–809
  Reign of Harun al-Rashid
  Harun al-Rashid rules as caliph.
• 803
  Execution of Ja'far the Barmakid
  Ja'far the Barmakid is executed.
• 813–833
  Caliphate of al-Ma'mun
  Al-Ma'mun rules as caliph.
• 836–892
  Samarra as seat of the caliphate
  The ancient capital at Samarra dates from 836 to 892 and provides outstanding evidence of the Abbasid Caliphate; it is the only surviving Islamic capital to retain its original plan, architecture and arts. ^{12Samarra Archaeological City · UNESCO World Heritage Centre ↗}
• 1258
  Mongol conquest of Baghdad
  The Mongols conquer the Abbasid Caliphate and sack Baghdad, murdering the caliph. ^{2Abbasid Dynasty · World History Encyclopedia ↗}
• 1250–1517
  Mamluk Sultanate and the shadow caliphate in Cairo
  Abbasid shadow caliphs are kept in Cairo by their Mamluk overlords until 1517 CE. ^{2Abbasid Dynasty · World History Encyclopedia ↗}
• 2007
  UNESCO World Heritage inscription of Samarra
  Samarra is inscribed as a UNESCO World Heritage site.