the cover of the nearby treelines, aim their bows directly at the advancing elephants. The Mongol archers' arrows threw the animals into such pain that they fled. Raid of Kaungsin The Mongol army pressed on after the monsoon season. In the following dry season of 1277–78, c. December 1277, a Mongol army of 3,800 men led by Nasr al-Din, son of Gov. Sayyid Ajjal, advanced to Kaungsin, which defended the Bhamo Pass. They occupied the fort and destroyed a large number of abandoned stockades. But they found the heat excessive and returned. Interlude (1278–1283) Despite the Mongol military success, the control of the borderlands remained contested. Pagan did not relinquish its claim to the frontier regions, and the Burmese, apparently taking advantage of Mongol preoccupations elsewhere, rebuilt their forts at Kaungsin and Ngasaunggyan later in 1278, posting permanent garrisons commanded by Einda Pyissi. But their control was short-lived. The Great Khan's attention turned to Southeast Asia once more in 1281. He had mixed success: his vaunted forces finished off the last of the Song in 1279 but had again failed to take Japan in 1281. That year, the Mongol emperor sent another mission to Pagan, demanding tribute yet again. The Burmese king was to send his ten senior ministers accompanied by one thousand cavalry officers to the emperor's court. (With Champa, the emperor summoned the king of Champa himself to Beijing.) At Pagan, Narathihapate deliberated with his court for an appropriate response but ultimately refused to submit. The Burmese court may have been counting on another limited border war but the emperor now ordered an invasion of northern Burma. (He also ordered an invasion of Champa, whose king too had refused to submit.) Throughout 1282, the Mongol command made preparations for the upcoming invasions of Champa and northern Burma. The objective of the Burma campaign was to take over northern Burma but no further; the emperor did not sanction an attack on Pagan itself. At least one army consisted of 14,000 men of the erstwhile Khwarezmid Empire under the command of Yalu Beg was sent to Yunnan to reinforce the Burma invasion force, which again was made up of Turks and other central Asians. On the Burmese side, the king managed to raise an army although given his low standing with his vassals, he probably could not have raised a large one. By mid-1283, a Burmese army led by generals