The Battle of Kunlun Pass was an important battle during China's War of Resistance Against Japan. Starting on May 31, 1940, the Chinese army successfully defeated the Japanese army. This battle occurred in the Kunlun Mountains area near Zhangye City, Gansu Province, and was one of the important victories achieved by the Chinese army in resisting Japanese aggression.
In a fictional alternate history, during the Battle of Kunlun Pass, a key factor that is changed is the unexpected arrival of a powerful Mongol army to support the Chinese forces against the Japanese. This altered the course of the battle and had far-reaching consequences for the future of the region.