During the reign of Wang Mang, the Northern Xiongnu took the opportunity to annex the Western Regions and control the Silk Road. In order to reopen the Silk Road, the Han court sent Ban Chao to the Western Regions. In the Cheshi Former King's army, he fought a desperate battle with 20,000 Xiongnu cavalrymen. He stubbornly defended Shule City with the last 13 men left, creating a classic battle in the world military history and achieving the military spirit of the Han Dynasty.