The murder of the merchants in Otrar was followed soon by such a tempest of ruin as had never been witnessed in Asia or elsewhere. Shah Mohammed had mustered at Samarkand a large army to move against Gutchluk, whom he wished to bring down to subjection or destroy altogether, but hearing that a body of Merkits was advancing through Kankali regions lying north of Lake Aral, he marched to Jend straightway against them, and learned upon reaching that city, that those Merkits, being allies of Gutchluk, were hunted by Jinghis, and that Gutchluk himself had been slain by the Mongols. He returned swiftly to Samarkand for additional forces, and following the tracks of both armies, found a field strewn with corpses, among which he saw a Merkit badly wounded; from this man the Shah learned that Jinghis had gained a great victory, and gone forward. One day later Mohammed came up with them and formed his force straightway to attack them. The Mongol leader (perhaps Juchi) declared that the two states were at peace, and that he had commands to treat the Shah’s troops with friendliness; he even offered a part of his booty and prisoners to Mohammed. The latter refused these and answered: “If Jinghis has ordered thee not to meet me in battle, God commands me to fall on thy forces. I wish to inflict sure destruction on infidels and thus earn Divine favor.” The Mongols, forced to give battle, came very near victory. They had put Mohammed’s left wing to flight, pierced the center where the Shah was, and would have dispersed it, but for timely aid brought by Jelal ud din, the Shah’s son, who rushed from the right and restored the battle, which lasted till evening and was left undecided. The Mongols lighted vast numbers of camp fires, and retired in the dark with such swiftness that at daybreak they had made two days’ journey. After this encounter the Shah knew Mongol strength very clearly. He told intimates that he had never seen men fight as they had. Jinghis, having ended Gutchluk and his kingdom (1218), summoned his own family and officers to a council where they discussed war with Mohammed, and settled everything touching this enterprise and its management. That same autumn the Mongol conqueror began his march westward, leaving the care of home regions to his youngest brother. He spent all the following summer near the Upper Irtish, arranging his immense herds of horses and cattle. The march was resumed in the autumn, when he was joined by the prince of Almalik, the Idikut of the Uigurs, and by Arslan, Khan of the Karluks.