looted and then destroyed mosques, palaces, libraries, and hospitals. Priceless books from Baghdad's thirty-six public libraries were torn apart, the looters using their leather covers as sandals. Grand buildings that had been the work of generations were burned to the ground. The House of Wisdom (the Grand Library of Baghdad), containing countless precious historical documents and books on subjects ranging from medicine to astronomy, was destroyed. Claims have been made that the Tigris ran red from the blood of the scientists and philosophers killed. Citizens attempted to flee, but were intercepted by Mongol soldiers who killed in abundance, sparing no one, not even children. The caliph al-Musta'sim was captured and forced to watch as his citizens were murdered and his treasury plundered. According to most accounts, the caliph was killed by trampling. The Mongols rolled the caliph up in a rug, and rode their horses over him, as they believed that the earth would be offended if it were touched by royal blood. All but one of al-Musta'sim's sons were killed, and the sole surviving son was sent to Mongolia, where Mongolian historians report he married and fathered children, but played no role in Islam thereafter. Hulagu had to move his camp upwind of the city, due to the stench of decay from the ruined city. The historian David Morgan has quoted Wassaf (who himself was born 7 years after the razing of the city in 1265) describing the destruction: "They swept through the city like hungry falcons attacking a flight of doves, or like raging wolves attacking sheep, with loose reins and shameless faces, murdering and spreading terror...beds and cushions made of gold and encrusted with jewels were cut to pieces with knives and torn to shreds. Those hiding behind the veils of the great Harem were dragged...through the streets and alleys, each of them becoming a plaything...as the population died at the hands of the invaders." Aftermath Hulagu left 3,000 Mongol soldiers behind to rebuild Baghdad. Ata-Malik Juvayni was later appointed governor of Baghdad, Lower Mesopotamia, and Khuzistan after Guo Kan went back to the Yuan dynasty to assist Kublai's conquest over the Song dynasty. Hulagu's Nestorian Christian wife, Dokuz Khatun, successfully interceded to spare the lives of Baghdad's Christian inhabitants. Hulagu offered the royal palace to the Nestorian Catholicos Mar Makikha, and ordered a cathedral to be built for him. Initially, the fall of Baghdad came as