The Abbasid Caliphate, founded by Abu al-‘Abbās ‘Abdu'llāh ibn Muhammad as-Saffāḥ, the great-great-grandson of Muhammad's uncle Abbas, in 749, had ruled northeastern Africa, Arabia, and the Near East, even though their rule had by 1258 shrunk to only southern and central Iraq. The Abbasids' seat of power for almost 500 years was Baghdad, a city considered to be the jewel of Islam and one of the largest and most powerful cities in the world. But under attack from the Mongols, the city fell on , a loss often considered in the Muslim world as the single most catastrophic event in the history of Islam, the end of the Islamic Golden Age. The Christian Georgians had been the first to breach the walls, and as described by historian Steven Runciman, "were particularly fierce in their destruction". When Hulagu conquered the city, the Mongols demolished buildings, burned entire neighborhoods, and massacred nearly all the men, women, and children. But at the intervention of Doquz Khatun, the Christian inhabitants were spared.