In the eighteenth year of Yongping (75), the Northern Xiongnu attacked the Eastern Han Dynasty, and although many countries in the Western Regions had submitted to the Han Dynasty, due to the unstable internal situation of the Han Dynasty at that time, the Yanqi and Guizi countries in the Western Regions fell to the Xiongnu. The two armies also jointly attacked the Western Regions Capital Protectorate, and the entire army of Duhu Chen Mu was destroyed, the Northern Xiongnu army surrounded Guanyu at Liuzhong City, and the Cheshi State once again rebelled and attacked Geng Gong with the Xiongnu.
In the Central Plains, the Eastern Han Court coincided with the death of Emperor Ming of Han, and no troops were sent to save the crisis in the Western Regions during the great funeral. Geng Gong, the lone army in the western region, had to resist desperately, and when the food ran out, he boiled the animal tendons and leather on the armor and crossbow to fill the hunger.
Geng Gong shared the hardships with the soldiers, and the morale of the whole army was still high. At that time, The queen of Cheshi was a descendant of the Han people, and often secretly provided intelligence and grain to Geng Gong, gave a lot of help to the Han army, the brutal battle caused the Han army to suffer heavy casualties, and finally only dozens of people were left, the Xiongnu were expected to fall into a desperate situation, Geng Gong would surrender, so he sent emissaries to persuade Geng Gong to surrender on favorable terms, and Geng Gong lured the Xiongnu emissaries to the city to kill him personally. Subsequently, Geng Gong burned the corpses of xiongnu emissaries with fire at the head of the city to show his determination to protect the territory of the Han family. The Xiongnu were furious and sent reinforcements to besiege Geng Gong, but they were never able to break through this isolated city in the western region, and the scene at the head of the city that day corresponded to Yue Fei's words a thousand years later: "Zhuangzhi is hungry for meat, laughing and talking about thirst for Xiongnu blood." At this time, Emperor Zhang of Han ascended the throne, and the political situation in the Eastern Han Dynasty was stable. Another letter of help from Guan Pet, a lone army in the Western Regions, arrived at the Eastern Han court, and Emperor Zhangdi of Han sent the general Geng Bingtun to guard Jiuquan, and sent Jiuquan Taishou Qin Peng to send troops from Zhangye, Jiuquan, the three counties of Dunhuang, and Shanshan, totaling more than 7,000 people, to the rescue.
Qin Peng and others led an army to assemble in Liuzhong, quickly marched to raid the Cheshi state, attacked Jiaohe City, killed a total of 3,800 people, captured more than 3,000 people, the Xiongnu heard the news panicked and fled, Cheshi once again surrendered to the Eastern Han. At this time, Guan Yu had died, and Geng Gong of Shule City had no news, and the Western Aid Army planned to lead troops back to the east. Fan Qiang, the general sent by Geng Gong to Dunhuang, was in the army, and he insisted on rescuing his comrades-in-arms, and the generals who aided the Western Army sent two thousand rescue troops to Fan Qiang. Although there was no news of comrades-in-arms for a long time, although the road had encountered snow that was more than a mile deep, Fan Jiang still led the reinforcements day and night, and finally reached the city of Shule, Geng Gong and others heard the soldiers and horses hissing, thinking that the Xiongnu had come.
Fan Qiang shouted: "I Fan Qiangye, the Han Army greeted the lieutenant's ear", the generals in the city heard this, and they wept with joy, and the crowd shouted long live! When the city gate was opened, the twenty-six remaining Han soldiers who insisted on the isolated city of Shule hugged and wept with their comrades-in-arms, even if they looked back on this moment a thousand years later, it was extremely moving.
The next day, Geng Gong and his party returned with the rescuers, and the Xiongnu sent troops to pursue them continuously, and the Han army fought and retreated. Twenty-six warriors set out from Shule and slept all the way to Yumen in March, leaving only thirteen.
According to the Book of the Later Han Dynasty, when these thirteen men arrived at the Yumen Pass, they "dressed in clothes and died, describing them as withered." Zhonglang arranged for Zheng Zhong to bathe Geng Gong and his subordinates, change their clothes and hats, and wrote to the imperial court:
"Geng Gong held the isolated city with a single soldier, and when the Xiongnu rushed, against tens of thousands of people. For more than a month, his heart was exhausted, he dug mountains into wells, boiled crossbows for grain, and out of the hope of dying without a lifetime, he killed and injured thousands of ugly people before and after, and he was loyal and courageous, and he was not ashamed of the Great Han. ”
Geng Gong led hundreds of Han generals to face tens of thousands of Xiongnu troops and held the city of Shule. The court of the Eastern Han Dynasty even rushed thousands of miles to rescue Geng Gong's lone army, creating the dignity and glory that the great Han people would save even though they were far away.
If Chen Tang's "those who commit crimes against strong hans will be punished from afar" represent the imperial prestige of a powerful empire, then a great Han people like Geng Gong will be saved from afar, which embodies the dignity and glory of the people. Geng Gong's defense of Shule is a very arduous defensive battle, and the return of the thirteen generals to Yumen is a thousand-mile rescue that shines through the ages.
In the whole battlefield situation, the strategy adopted by the Xiongnu was to take advantage of the fact that the Han Dynasty forces had no time to look west to unite with the countries of the Western Regions to attack the Eastern Han Stronghold in the Western Regions, so as to achieve the purpose of re-occupying the Western Regions.
The Eastern Han Dynasty adopted the strategy of holding on to the garrison in the western region and relying on the Jiancheng Iron Army to resist the Xiongnu attack.
The end of the war was that Geng Gongguan and other generals held the isolated city alone, and finally waited for the Eastern Han reinforcements to repel the Xiongnu attack.