Caliph Abu-al-Abbas was the founder of the Abbasid Caliphate, the most celebrated and longest lived Arab dynasty in Islam. It ruled (from Baghdad) 750 to 1258 A.D. Abu-al-Abbas was a man of a most determined personality. He was purely intellectual, guided by logic and lacking in emotions or the weaknesses bred by affection or pity(1). He came to power as a result of a successful revolution which overthrew the Umayyad Caliphate of Damascus.