Page "Siege" Paragraph 49

However, the Chinese were not completely defenceless, and from AD 1234 until 1279 the Southern Song Chinese held out against the enormous barrage of Mongol attacks.

Much of this success in defense lay in the world's first use of gunpowder ( i. e. with early flamethrowers, grenades, firearms, cannons, and land mines ) to fight back against the Khitans, the Tanguts, the Jurchens, and then the Mongols.