Not sure if Mongols are -entirely- responsible for the decline. We should also consider the shift of international trade from land to sea, and subsequent loss o

Not sure if Mongols are -entirely- responsible for the decline. We should also consider the shift of international trade from land to sea, and subsequent loss of contact with external world, as the possible culprit. (Consider the Ottomans, for example). That said, here's a famous quote: O would that my mother had never borne me, that I had died before and that I were forgotten [so] tremendous disaster such as had never happened before, and which struck all the world, though the Muslims above all . . . Dadjdjal [Muslim Anti-Christ] will at least spare those who adhere to him, and will only destroy his adversaries. These [Mongols], however, spared none. They killed women, men, children, ripped open the bodies of the pregnant and slaughtered the unborn. - Ibn al-Athir (1233–1160)