Today in 1258 Baghdad was lost by the Abbasids to Hulagu Khan and his Mongolian forces. During the sack of the city the Great Library and its books were destroyed, although in the long run the invasion led to a flourishing of learning under the Ilkhanid Dynasty.
Image from a copy from the 1430s of the
Jami al-tawarikh(Compendium of Chronicles)
by Rashid-al-Din Hamadani
now in the BNF, Paris