Notwithstanding the attempts to bring equality to all Muslims, rule in the Umayyad Empire largely remained in the hands of Arabs. The growing numbers of mawali quickly became the intellectual leaders, the bureaucrats, and the commercial elite of the Islamic community. Discontent and resentment of the Umayyads was growing as more and more realized that they still were not equal. The mawali, therefore, were more than willing to back dissident Islamic groups who aimed at overthrowing the Umayyads. Furthermore, the Shi'ite Muslims-whose dreams of having a descendant of Muhammad lead the Islamic community were quashed between A.D. 661-680-opposed the Umayyads.
In fact, in the first half of the eighth century, a Shi'ite revolutionary movement called the Hashimites (claiming a connection to the family of Muhammad) began to support a group called Abbasids (descendants of Muhammad's uncle Abbas). The Abbasids used the Shi'ite revolutionaries and the discontent mawali to gain support and power in a province of eastern Iran called Khurasan. There, in the year A.D. 747, a Persian convert named Abu-Muslim unfurled a black banner of revolution on behalf of the Abbasids. From Khurasan, the revolt spread west and reached Kufa in 749, and there laid claim to the caliphate on behalf of an Abbasid named Abu al-Abbas. The following year, A.D. 750, Abu-Muslim's troops defeated the Umayyad army and brought the Umayyad empire to an end. The only member of the Umayyad family to escape made a difficult journey across North Africa and reached Spain where he founded a separate Ummayad caliphate that lasted into the eleventh century. But the Middle East proper came once again under the sway of Muhammad's clan (Hashim) through his uncle's lineage.
Some have seen the Abbasid revolution and the subsequent development of the Abbasid Empire as a Persianization of a former Arab-Muslim empire-in effect an overthrow of the Arabs by the Persians. This view is oversimplified. As already shown, the Abbasids were Arabs-descendants of Muhammad's uncle Abbas and members of the Hashimite clan. We know that supporters of the Abbasids included Arabs and Persians, Shi'ites and members of the emerging Sunni majority, all uniting to overthrow the Umayyad Dynasty, which amounted to an Arab tribal aristocracy. The Abbasid revolution also symbolized the desire for a more egalitarian Muslim community based on The principles of the Islamic religion. Furthermore, the revolution contributed to rising expectations among the groups involved (Arabs, Persians, Shi'ites) for the achievement of those ends.
At the time of the Abbasid takeover, Baghdad was a tiny Persian village on the Tigris north of Kufa. Under the second Abbasid caliph (A.D. 762), the center of the new Abbasid Empire was moved to Baghdad. It was officially named Madinat al-Salam ("city of peace"). Baghdad was a more functional center than Damascus had been: it was more centrally situated than Damascus had been; it was located on the main trade route between the Mediterranean and the Gulf (meaning easier access to Europe and Asia); and it was closer to the areas of Abbasid support, mainly Khurasan.
But internal tensions continued to grow under the Abbasids. Revolts were more frequent and varied. The Shi'ites had been left somewhat in the dark about whom they were actually supporting in the revolution. Abu-Muslim, a Persian mawla it turns out, acted in the name of one from the "house of the Prophet" (Ahl al-Bayt), but it was not made clear who that leader would be. No doubt, the Shi'ites were hoping a blood descendant of Muhammad would replace the Umayyads. When they realized they had been used to replace the Umayyads with the Abbasids (descendants of Muhammad's uncle), they were once again resentful. The result was two major revolts and many minor revolts among the Shi'ites.
Persian groups also revolted. When Abu-Muslim was executed, certain Persians blamed Mansur, the ruling Abbasid caliph at the time. Furthermore, the suppression of pre-Islamic Persian religious traditions-Zoroastrianism and some other smaller sects-caused an underlying resentment that fed into Persian revolts against Abbasid rule. Finally, Abbasid favoritism toward the eastern provinces (in Iraq and Iran) fostered resentment among the once-privileged Syrians. As a result, Syrians joined in many minor rebellions against the Abbasids, none of which were successful.
Increasing Persian influence during the Abbasid period alleviated some of the resentment among their camp. The cosmopolitan nature of the Abbasids allowed many Persians, especially from Iraq and Iran, to rise to positions in the Abbasid administration and in the army, the latter replacing the Arab and Syrian forces favored by the Umayyads. Some Persians became Islamic religious scholars (ulama, meaning "those who know") and helped to shape Islamic law and religion. Persian bureaucrats who held high positions (provincial governors, tax collectors, military commanders, etc.) bore the Arabic title wazir (Persian vizier), meaning "burden bearer." In the long run, these improvements had a downside for the Abbasid rulers, however-namely, the rise of Persians to positions of influence prepared the way for breakaway Persian dynasties in Iran-the Tahirids (A.D. 861-873) and the Saffarids (A.D. 861-1465).
Cultural contributions of the Abbasid period included the development of Islamic institutions and ways of thinking: Islamic jurisprudence (the formal science of law) was developed, a systematic theology emerged from debates among legal scholars, and Islamic scholars dabbled with Greek philosophy. In literature, the Abbasid period saw the collection of various stories into a classic called the Arabian Nights (Aladdin and his lamp, Sinbad the Sailor, genies, etc.). In the ninth century, a Persian scholar by the name of Ibn Sina-known in the Western tradition as Avicenna-wrote a classic work on medicine that was still in use as a medical textbook in Europe as late as the eighteenth century. Theologians and philosophers such as Ibn Sina, Ibn Rushd (Latin Averroes), and others provided models for later Christian theology developed in the medieval period in Paris, Oxford, and Cambridge universities.
The early to mid A.D. 800s were important years for revealing an Islamic theology in flux. The caliph Ma`mun (r. A.D. 813-833) came to power on the heels of a bloody civil war that almost destroyed Baghdad. His interest in philosophical and theological debate led him to espouse the doctrines of the Mu'tazila, a group of rationalist theologians who attempted to synthesize Greek philosophy with Islam. The Mu'tazila stressed free will over predestination and the createdness of the Koran (in temporal time) over its uncreatedness (eternal), which was argued by more conservative-thinking theologians. Ma'mun set up a religious test for each high ranking Islamic official or qadi (judge). One question they had to answer was whether they believed God created all things, including the Koran. A "yes" answer meant they were Mu'tazilites; a "no" answer meant they were not, and they were persecuted and often, if not always, thrown in prison. This Mu'tazilite policy continued during the two succeeding caliphs after Ma'mun, but was ended by a more orthodox movement under the leadership of Ahmad Ibn Hanbal, who gained legal followers and established the Hanbali school of Islamic law (one of four major schools).
