What Was the Abbasid Caliphate?

Gold coins with Koranic verses on them, Abbasid Caliphate.
Abbasid Caliphate gold coins minted by the Islamic caliphate in Baghdad. via Wikipedia

Definition:

The Abbasid Caliphate, which ruled most of the Muslim world from Baghdad, in what is now Iraq, lasted from 750 CE to 1258. It was the third Islamic caliphate, and overthrew the Umayyad Caliphate to take power in all but the western-most fringe of Muslim holdings at that time - Spain and Portugal (known as the al-Andalus region).

After they defeated the Ummayads, with significant Persian assistance, the Abbasids decided to de-emphasize ethnic Arabs and recreate the Muslim caliphate as a multi-ethnic entity. As part of that reorganization, in 762 they moved the capital from Damascus, in what is now Syria, northeast to Baghdad, not far from Persia (Iran).

Early in the Abbasid period, Islam exploded across Central Asia, although usually the elites converted and then the religion trickled down gradually to ordinary people. This was not "conversion by the sword." Incredibly, just one year after the fall of the Umayyads, an Abbasid army was fighting against the Tang Chinese in what is now Kyrgyzstan, in the 751 CE Battle of Talas River. Although Talas River seemed like just a small skirmish, it had important consequences - it helped to set the boundary between the Buddhist and Muslim spheres in Asia, and also allowed the Arab world to learn the secret of paper-making from captured Chinese artisans.

The Abbasid period is considered a Golden Age for Islam. Abbasid caliphs sponsored great artists and scientists; great medical, astronomical, and other scientific texts from the classical period in Greece and Rome were translated into Arabic, saving them from being lost. While Europe languished in what was once called its "Dark Ages," Muslim thinkers in the Muslim world expanded upon the theories of Euclid and Ptolemy. They invented algebra, named stars like Altair and Aldebaran, and even used hypodermic needles to remove cataracts from human eyes. This was also the world that produced the stories of the Arabian Nights; the tales of Ali Baba, Sinbad the Sailor, and Aladdin came from the Abbasid era.

The Golden Age of the Abbasid Caliphate ended on February 10, 1258, when Genghis Khan's grandson, Hulagu Khan, sacked Baghdad. The Mongols burned the great library in the Abbasid capital, and killed the Caliph Al-Musta'sim.

Between 1261 and 1517, surviving Abbasid caliphs lived under Mamluk rule in Egypt, wielding more or less control over religious matters while having little to no political power. The last Abbasid caliph, Al-Mutawakkil III, supposedly handed over the title to the Ottoman Sultan Selim I in 1517.