Tan Daoji, a native of Gaoping during the Southern Dynasties, served as a vanguard during Emperor Wu of Song's northern expedition. He fought valiantly, and after a difficult campaign, captured 4,000 prisoners in Luoyang. When other generals suggested executing them to intimidate the enemy, Daoji retorted, "We came to bring peace to the people and punish wrongdoers, how can we indiscriminately kill the innocent?" He released all the captives, earning the Southern Song army popular support.

In the seventh year of Emperor Wen of Song's reign, the Southern Song forces suffered a defeat at Huatai. Emperor Wen dispatched Daoji for reinforcement. Daoji achieved a great victory over the Northern Wei army in Shouzhang, engaging in more than 30 battles over 20 days, eventually reaching Licheng (modern-day Jinan, Shandong). However, Huatai had already fallen, and Daoji's troops were running out of provisions. When the Northern Wei army learned of this, everyone in Daoji's camp was terrified. Yet, Daoji remained composed. He ordered his soldiers to measure sand in their tents at night, lightly sprinkling their meager remaining grain over it. After a night of this simulated measuring, the next morning, he commanded his troops to wear their heavy armor and retreat south. He himself, dressed in simple clothes, sat casually in a carriage, chatting and laughing, following at the rear. The Southern Song army safely returned.

From then on, the Northern Wei army greatly feared him, with soldiers even using his image to ward off evil. Later, Emperor Wen, swayed by false accusations, had Daoji executed. At his death, Daoji glared, threw his turban to the ground, and declared, "Are you not destroying your own Great Wall?"

Fourteen years after Daoji's death, the Northern Wei army advanced to Guabu, north of the Yangtze River. From Shitoucheng, separated by just a river, Emperor Wen of Song sighed with regret, "If Tan Daoji were still alive, they would not be acting like this."