Abbasid (, '''') is the dynastic name generally given to the caliph of Baghdad, the second of the two great Sunni dynasties of the Arab Empire, that overthrew the Umayyad caliphs from all but Spain. It was built by the descendant of Muhammad's youngest uncle, Abbas ibn Abd al-Muttalib. It seized power in 750 CE and shifted the capital from Damascus to Baghdad. It flourished for two centuries, but slowly went into decline with the rise to power of the Turkish army it had created, the Mamluks. Within 150 years of gaining power across Iran, they were forced to cede power to local dynastic amirs who only nominally acknowledged their power, and had to cede Al Andalus to an escaped Umayyad royal and the Maghreb and Ifriqiya to independent entities such as the Aghlabids and the Fatimids. Their rule was ended in 1258, when Hulagu Khan, the Mongol conqueror, sacked Baghdad. While they continued to claim authority in religious matters from their base in Egypt, the dynasty's secular authority had ended. Descendants of the Abbasids include the al-Abbasi tribe who live northeast of Tikrit in modern-day Iraq.

The Rise

The Abbasid caliphs officially based their claim to the caliphate on their descent from Abbas ibn Abd al-Muttalib (AD 566 – 662), one of the youngest uncles of Muhammad, by virtue of which descent they regarded themselves as the rightful heirs of Muhammad as opposed to the Umayyads. The Umayyads were descended from Umayya, and were a clan separate from Muhammad's in the Quraish tribe.

The Abbasids also distinguished themselves from the Umayyads by attacking their secularism, moral character, and administration in general. The Abbasids also appealed to non-Arab Muslims, known as mawali, who remained outside the kinship-based society of Arab culture and were perceived of as a lower class within the Umayyad empire. Muhammad ibn 'Ali, a great-grandson of Abbas, began to campaign for the return of power to the family of Muhammad, the Hashimites, in Persia during the reign of Umar II, Muhammad ibn Ali.

During the reign of Marwan II, this opposition culminated in the rebellion of Ibrahim the Imam, the fourth in descent from Abbas. Supported by the province of Khorasan, he 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, with victory on the Greater Zab River (750), defeated the Umayyads and was proclaimed Caliph.

Political Situation

Consolidation and schisms

The first change the Abbasids made was to move the empire's capital from Damascus, in Syria, to Baghdad in Iraq. This was to both appease as well to be closer to the Persian ''mawali'' support base that existed in this region more influenced by Persian history and culture, and part of the Persian mawali demand for less Arab dominance in the empire. Baghdad was established on the Tigris River in 762 CE. A new position, that of the vizier, was also established to delegate central authority, and even greater authority was delegated to local emirs. Eventually, this meant that many Abbasid caliphs were eventually relegated to a more ceremonial role than under the Umayyads, as the viziers began to exert greater influence, and the role of the old Arab aristocracy was slowly replaced by a Persian bureaucracy. Applied History Research Group , University of Calagary, "[http://www.ucalgary.ca/applied_history/tutor/islam/fractured/ The Islamic World to 1600", Last accessed August 26, 2006

Rift with the Arabs

The Abbasids had depended heavily on the support of Persians in their overthrow of the Umayyads. Abu al-'Abbas' successor, al-Mansur, moved their capital from Damascus to the new city of Baghdad and welcomed non-Arab Muslims to their court. While this helped integrate Arab and Persian cultures, it alienated many of their Arab supporters, particularly the Khorasanian Arabs who had supported them in their battles against the Umayyads.

These fissures in their support led to immediate problems. The Umayyads, while out of power, were not destroyed. The only surviving member of the Umayyad royal family, which had been all but annihilated, ultimately made his way to Spain where he established himself as an independent Emir (Abd ar-Rahman I, 756). In 929, Abd ar-Rahman III assumed the title of Caliph, establishing Al Andalus from Córdoba as a rival to Baghdad as the legitimate capital of the Islamic Empire.

Rift with the Shia

The Abbasids also found themselves at odds with the Shias, many of whom had supported their war against the Umayyads, since the Abbasids claimed legitimacy by their familial connection to Muhammed. Once in power, the Abbasids embraced Sunni Islam and disavowed any support for Shi'a beliefs. That led to numerous conflicts, culminating in an uprising in Mecca in 786, followed by widespread bloodshed and the flight of many Shi'a to the Maghreb, where the survivors established the Idrisid kingdom. Shortly thereafter, Berber Kharijites set up an independent state in North Africa in 801.

Loss of North Africa

Within 50 years the Idrisids in the Maghreb and Aghlabids of Ifriqiya and a little later the Tulunids and Ikshidids of Misr were effectively independent in Africa.

Communication with Provinces

The Abbasid leadership had to work hard in the last half of the eighth century (750-800), under several competent caliphs and their viziers to overcome the political challenges created by the far flung nature of the empire, and the limited communication across it and usher in the administrative changes to keep order. Brauer, Ralph W, ''Boundaries and Frontiers in Medieval Muslim Geography '', Diane Publishing Co., Dec 1, 1995, ISBN 0-87169-856-0, pg 7-10. While the Byzantine Empire was fighting Abbasid rule in Syria and Anatolia, military operations during this period were minimal, as the caliphate focused on internal matters as local governors, who, as a matter of prodecure, operated mostly independently of central authority. The problem that the caliphs faced was that these governors had begun to exert greater autonomy, using their increasing power to make their positions hereditary.

Fracture of Central Authority

Even by 820 CE, the Samanids had begun the process of exercising independent authority in Transoxiana and Greater Khorasan, the Shia Hamdanids in Northern Syria, and the successive Tahirid, Alid and Saffarid dynasties of Iran. By the early 10th century, the Abbasids almost lost control to the growing Persian faction known as the Buwayhids that replaced the Samanids as the Buwayhids were quietly able to assume real power in the bureaucracy at Baghdad.

All these autonomous provinces slowly took on the characteristic of de facto states with hereditary rulers, armies, and revenues and operated under only nominal caliphal suzeranity, which may not necessarily be reflected by any contribution to the treasury. The eventual rise of the Ghaznavid Empire and the Seljuks to displace all these factions marked the end of Abbasid political dominion over the area.

Loss of Power

Mahmud of Ghazni proclaimed the title of Sultan vs. the Emir that had been in more common usage, signifying the Ghaznavid Empire's independence from Caliphial authority even as a matter of form. By the 11th century, this was demonstrated by no longer mentioning the caliphs name in the Friday Khutba, or by striking it off from their coinage by the Seljuks, Sultanate of Rûm, Khwarezmshahs, Almoravids etc. The Fatimids contested the Abbassids for even the titluar authority. The Buwayhids were then defeated in the mid-11th century by enlisting the aid of the Seljuks under Toghril Beg. The Seljuks however then themselves took over defacto lordship of the empire, and their leader bestowed the title by the caliph of the Sultan of the East and the West, reflecting his power, and exerted influence power over the Abbasids as a matter of form by publicly pledging allegiance to them leaving the Caliph in control of little actual territory beyond Baghdad.

The end of the dynasty

Hulagu Khan sacked Baghdad on (February 10, 1258), causing great loss of life. Hulagu, and many others feared the ensuing a shock of nature, if the blood of Al-Musta'sim, the last reigning Abbasid caliphate in Baghdad, a direct descendent of Muhammads's uncle, was spilled. Despite having taken advice from Learned Shiites of Persia that no such calamity had happened after the deaths of John the Baptist, Jesus Christ, or the Shiite saint Hosein, as a precaution, Hulagu had Al-Musta'sim wrapped in a carpet and then trodden to death by horses on February 20, 1258. Al-Musta'sim family was also executed, with the lone exceptions of his youngest son and a daughter who were sent to Mongolia to be slaves in the harem of Hulagu.Annals of history: Invaders: Destroying Baghdad by Ian Frazier, in The New Yorker 25 April 2005

The Abbasids still maintained a feeble show of authority, confined to religious matters, in Egypt under the Mamluks, but the dynasty finally disappeared with Al-Mutawakkil III, who was carried away as a prisoner of the palace to Constantinople by Selim I where he only had ceremonial role, until his death when the Caliphate title was transferred to Selim I.

The Mamluks

In the 9th century, the Abbasids created an army loyal only to their caliphate, drawn mostly from Turkish slaves, known as Mamluks, with some Slavs and Berbers participating as well. This force, created in the reign of al-Ma'mun (813 – 833), and his brother and successor al-Mu'tasim (833 – 842), prevented the further distintegration of the empire.

The Mamluk army, though often viewed negatively, both helped and hurt the caliphate. Early on, it provided the government with a stable force to deal with domestic and foreign problems. However, creation of this foreign army and al-Mu'tasim's transfer of the capital from Baghdad to Samarra created a division between the caliphate and the peoples they claimed to rule. In addition, the power of the Mamluks steadily grew until al-Radi (934 – 941) was constrained to hand over most of the royal functions to Mahommed bin Raik. In the following years, the Buwayhids, who were Shi'ites, seized power over Baghdad, ruling central Iraq for more than a century.

Science under the Abbasids

The reigns of Harun al-Rashid (786 – 809) and his successors fostered an age of great intellectual achievement. In large part, this was the result of the schismatic forces that had undermined the Umayyad regime, which relied on the assertion of the superiority of Arab culture as part of its claim to legitimacy, and the Abbasids' welcoming of support from non-Arab Muslims. It is well established that the Abbasid caliphs modeled their administration on that of the Sassanids.Hamilton Gibb. ''Studies on the civilization of Islam''. Princeton University Press. 1982. ISBN 0-691-05354-5 p.66 One Abbasid caliph is even quoted as saying:

:''"The Persians ruled for a thousand years and did not need us Arabs even for a day. We have been ruling them for one or two centuries and cannot do without them for an hour."''Bertold Spuler. ''The Muslim World. Vol.I The Age of the Caliphs.'' Leiden. E.J. Brill. 1960 ISBN 0-685-23328-6 p.29

A number of medieval thinkers and scientists living under Islamic rule played a role in transmitting Islamic science 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 Euclides and Claudius Ptolemy. These recovered mathematical methods were later enhanced and developed by other Islamic scholars, notably by Al-Biruni, and Abu Nasr Mansur.

Medicine was an area of science that advanced particularly during the Abbasids' reign. During the ninth century, Baghdad contained over 800 doctors, and great discoveries in the understanding of anatomy and diseases were made. The clinical distinction between measles and smallpox was discovered during this time. Famous scientist Ibn Sina (known to the West as Avicenna) produced treatises and works that summarized the vast amount of knowledge that scientists had accumulated, and is often known as the father of modern medicine. The work of him and many others directly influenced the research of European scientists during the Renaissance and even later.

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