The Legend of the Condor Heroes

The next day Genghis Khan held another general assembly. The vanguard was under Chagatai and Ogedei's command. The left flank was under Jochi's command, while the right was under Guo Jing's. Each of the vanguard, left and right units were thirty thousand men strong. Genghis Khan and Tuolei commanded over sixty thousand soldiers as the main army. Each soldier rode on one of a pair of horses; they would ride one horse at a time to conserve the horses' strength. The officers took even more horses. With one hundred and fifty thousand men, they took with them nearly a million horses.

The horns were sounded, the drums were beaten, the noise was deafening. The thirty-thousand strong vanguard cavalry unit started to gallop majestically to the west. The great army moved farther and farther west, entering Khoresm territory with irresistible force. Muhammad's army was bigger, but they were not the Mongolian's army match.

Guo Jing led his unit destroying cities and killing the enemies, he had rendered not a few merits.