Abbasid was the dynastic name generally given to the caliphs of Baghdad, the second of the two great Sunni dynasties of the Muslim empire. The Abbasid caliphs officially based their claim to the throne on their descent from Abbas ibn Abd al-Muttalib (AD 566-652), one of the youngest uncles of Muhammad, in virtue of which descent they regarded themselves as the rightful heirs of the Prophet as opposed to the Umayyads. The Umayyads were descended from Umayya, and were a clan separate from Muhammad's in the Quraish tribe.

Throughout the second period of the Umayyads, representatives of this family were among their most dangerous opponents, partly by the skill with which they undermined the reputation of the reigning princes by accusations against their orthodoxy, their moral character and their administration in general, and partly by their cunning manipulation of internecine jealousies among the Arabic and non-Arabic subjects of the empire.

During the reign of Marwan II this opposition culminated in the rebellion of Ibrahim the Imam, the fourth in descent from Abbas, who, supported by the province of Khorasan, achieved considerable successes, but was captured (AD 747) and died in prison (as some hold, assassinated). The quarrel was taken up by his brother Abdallah, known by the name of Abu al-'Abbas as-Saffah, who after a decisive victory on the Greater Zab river (750) finally crushed the Umayyads and was proclaimed caliph.

The history of the new dynasty is marked by perpetual strife and the development of luxury and the liberal arts, in place of what their opponents identified as old-fashioned austerity of thought and manners. The Abbasids also persecuted descendants of Ali ibn Abu Talib viewing them as threats, and this in turn earned the dynasty great disfavor with the Shia, who lost many of their leaders to the Abbasids. Mansur, the second of the house, who transferred the seat of government to the new city of Baghdad, fought successfully against the peoples of Asia Minor, and the reigns of Harun al-Rashid (786 - 809) and al-Ma'mun (813 - 833) were periods of extraordinary splendour.

Independent monarchs established themselves in Africa and Khorasan (an Umayyad prince had set up independent rule in Spain), and in the north-west the Byzantines successfully encroached.

The ruin of the dynasty came, however, from those Turkish slaves who were constituted as a royal bodyguard by al-Mu'tasim (833 - 842). Their power steadily grew until al-Radi (934 - 941) was constrained to hand over most of the royal functions to Mahommed bin Raik. Province after province renounced the authority of the caliphs, who became figureheads, and finally Hulagu Khan, the Mongol general, sacked Baghdad (February 28 1258) with great loss of life.

The Abbasids still maintained a feeble show of authority, confined to religious matters, in Egypt under the Mamelukes, but the dynasty finally disappeared with Motawakkil III , who was carried away as a prisoner to Constantinople by Selim I.

This age was marked by intellectual achievement. A number of medieval thinkers and scientists living under Islamic rule, many of them non-Muslims or heretical Muslims, played a role in transmitting Greek, Hindu, and other pre-Islamic knowledge to the Christian West. They contributed to making Aristotle known in Christian Europe. In addition the period saw the recovery of much of the Alexandrian mathematical, geometric and astronomical knowledge, such as that of Euclid and Claudius Ptolemy, and these recovered mathematical methods were later enhanced and developed by other Islamic scholars, notably by Al-Biruni, and Abu Nasr Mansur, who are thought to have first derived the Cosine rule, and applied it to spherical geometry.

Three speculative thinkers, the Persians al-Kindi, al-Farabi, and Avicenna, combined Aristotelianism and Neoplatonism with other ideas introduced through Islam.

See also History of Islam

Initial text from 1911 encyclopedia -- Please update as needed

Abbasid Caliphs of Baghdad

• Abu'l Abbas Al-Saffah 750 - 754
• Al-Mansur 754 - 775
• Al-Mahdi 775 - 785
• Al-Hadi 785 - 786
• Harun al-Rashid 786 - 809
• Al-Amin 809 - 813
• Al-Ma'mun 813 - 833
• Al-Mu'tasim 833 - 842
• Al-Wathiq 842 - 847
• Al-Mutawakkil 847 - 861
• Al-Muntasir 861 - 862
• Al-Musta'in 862 - 866
• Al-Mu'tazz 866 - 869
• Al-Muhtadi 869 - 870
• Al-Mu'tamid 870 - 892
• Al-Mu'tadid 892 - 902
• Al-Muktafi 902 - 908
• Al-Muqtadir 908 - 932
• Al-Qahir 932 - 934
• Al-Radi 934 - 940
• Al-Muttaqi 940 - 944
• Al-Mustakfi 944 - 946
• Al-Muti 946 - 974
• Al-Ta'i 974 - 991
• Al-Qadir 991 - 1031
• Al-Qa'im 1031 - 1075
• Al-Muqtadi 1075 - 1094
• Al-Mustazhir 1094 - 1118
• Al-Mustarshid 1118 - 1135
• Al-Rashid 1135 - 1136
• Al-Muqtafi 1136 - 1160
• Al-Mustanjid 1160 - 1170
• Al-Mustadi 1170 - 1180
• An-Nasir 1180 - 1225
• Az-Zahir 1225 - 1226
• Al-Mustansir 1226 - 1242
• Al-Musta'sim 1242 - 1258

Abbasid Caliphs in Cairo

• Al-Mustansir 1261
• Al-Hakim I 1262-1302
• Al-Mustakfi I 1302-1340
• Al-Wathiq I 1340-1341
• Al-Hakim II 1341-1352
• Al-Mu'tadid I 1352-1362
• Al-Mutawakkil I 1362-1383
• Al-Wathiq II 1383-1386
• Al-Mu'tasim 1386-1389
• Al-Mutawakkil I (restored) 1389-1406
• Al-Musta'in 1406-1414
• Al-Mu'tadid II 1414-1441
• Al-Mustakfi II 1441-1451
• Al-Qa'im 1451-1455
• Al-Mustanjid 1455-1479
• Al-Mutawakkil II 1479-1497
• Al-Mustamsik 1497-1508
• Al-Mutawakkil III 1508-1517

External link

• http://www.princeton.edu/~batke/itl/denise/abbasids.htm