Although many of us are familiar with the politics of the modern Middle East, I'm guessing most of us are not nearly as versed in its history. Today we'll try to rectify this a bit as we discuss the Abbasid Empire and their rulers, known as caliphs. To begin, the Abbasids ruled the Arab world from about 750 CE to 1258 CE. They took power after conquering the former empire of the Umayyads.