In 750 AD, the Umayyad caliphs were replaced by the Abbasid caliphs, who murdered all of the surviving Umayyad men but one. The Abbasids were less interested in the Mediterranean coast than the Umayyads had been, and the Abbasids therefore tended to
concentrate more on the plains of Iraq and Iran, and less on the coast: Israel, Syria, and Lebanon, and Egypt. In 762 AD the Abbasids moved their capital from Damascus in Syria to the new city of Baghdad (the h is silent) in Iraq (which is still the capital
of Iraq today). This shift can be seen as another example of the West Asian conflict between an orientation toward the land and an orientation toward the sea.
Baghdad was soon a big international city, where people spoke Aramaic, Arabic, and Persian. Many different groups of people lived there: Arabs, Persians, Jews, and Greeks. Many different gods were worshipped: there were Christians, Jews, and Zoroastrians, in addition to the Islamic majority. By the 800s Baghdad probably had nearly half a million people (that is half as big as Rome during the Roman Empire), and was the largest city in the world outside of China.
The one surviving Umayyad man fled from Damascus around the Mediterranean to Spain, where he founded the Umayyad Caliphate of Spain, and he and his successors ruled Spain for many years.
The Abbasids ruled all of West Asia and North Africa from 750 AD until about 1000, when they began to weaken. First North Africa broke away and formed independent kingdoms under the Fatimids. Then gradually the governors of each province - like the Samanids - began to act more and more independently, and the Turkish generals of the armies became less and less under the control of the Caliphs. The successes of the First Crusade in 1096 in taking over Jerusalem and much of Israel and Lebanon are due largely to the gradual decline of Abbasid power. In 1258 AD the Abbasid dynasty ended.