Huo Qubing
In the Battle of Hexi (121 BC), the Han forces had inflicted a major defeat to the Xiongnu. Emperor Wu desired to place firm control over the Hexi Corridor and decided to launch a large military offensive to purge the Xiongnu from the area. The campaign was undertaken in 121 BC by General Huo Qubing. Departing from Longxi that year, General Huo Qubing led light cavalry through five Xiongnu kingdoms, conquering the Yanzhi and Qilian mountain ranges from the Xiongnu.