The name camer from its ancestor al- Abbas; the uncle of Muhammad. In 750 Abbasid defeated the Umayyads and moved capital to Baghdad. All caliphs were descended from Abbas; member of Quraysh of Mecca, uncle of Muhammad. Caliphs were at first religious and political leader, but later became puppets in hands of Turkish soilder. Philosophy, medicine, math, and other science flourished during this time; Hellenistic.