Paul Freedman, professor of history at Yale, lectures on the Abbasid dynasty that took over the Islamic Caliphate in 750 and moved its capital to the newly built city of Baghdad. He traces how the Abbasids built a strong administrative apparatus and tax system that funded a cultural flowering, fed in part by the translation of classical Greek and Roman texts into Arabic. The lecture moves through the assimilation of conquered peoples and their ideas into the caliphate's intellectual life, closing with a look at Abbasid advances in mathematics and astronomy. Part of Freedman's Yale course The Early Middle Ages, 284-1000, recorded in fall 2011, the talk is organized into four chapters covering the Abbasids' rise, their cultural achievements, assimilation, and scientific contributions.