Hulaku, the sacker of Bagdad, had put the Caliph Mustasim to death, and the remnant of the Abbasids had kept up a shadowy succession at Cairo, under the protection of the Sultan of Egypt. Selim the Osmanli, when he entered Cairo as a conqueror in 1517, caused the contemporary Abbasid to cede his title, for what it was worth, to him and his successors.
The Persian Government, locked in a suicidal struggle with Rome, was powerless to make good the damage, and the shock of the Arab invasion made it irreparable . Under the Abbasid Caliphs of Bagdad the rest of the country preserved its prosperity, but in the thirteenth century Hulaku the Mongol finished the work of the floods, and under Ottoman dominion the Sawâd has not recovered.
Hulaku Khan, the fierce Mongol chief, had long had his eye on Baghdad as holding princely loot in all too slack a grip, for the Caliphate had been relying on Tartar mercenaries for years. He approached that queen of cities, as she then was, with a great host, lured the Caliph out to meet him by the promise of an alliance, and murdered the whole party, the Caliph being trampled to death.