King Min of Qi was extremely fatuous and fond of flattery. On one hand, he exploited and enslaved his people, and on the other, he massively expanded his army and invaded neighboring states without cause. This stirred up popular resentment and hatred from the various feudal lords. That year, the state of Yan sent its great general Yue Yi to attack Qi, capturing over 70 of its cities. In the end, only the cities of Ju and Jimo remained. At this time, a distant relative of the Tian clan of Qi, named Tian Dan, who was a minor market official, fled with his family to Jimo due to the chaos of war. Soon after, Yan forces attacked Jimo. The Jimo governor wanted to go out and fight, but Tian Dan advised him that Qi's military strength was weak and it was not suitable to engage the enemy. The governor ignored Tian Dan's advice, went into battle, and was defeated and killed. Then, the people pushed Tian Dan forward to be their general, defending the city of Jimo.
After Tian Dan took office, in order to expand the army, he even enlisted his own family members into the ranks, which earned him great admiration from many townspeople. Because Tian Dan was honest and virtuous, many people came to him to sign up for military service. Soon, the morale in Jimo City soared. The Yan general Yue Yi led troops to attack Ju and Jimo, besieging them for three full years without success. Jimo was a city difficult to attack but easy to defend, with ample food supplies, so Yue Yi planned for a prolonged war. Tian Dan anticipated Yue Yi's strategy and knew he was a skilled general, realizing that as long as Yue Yi led the Yan army, Jimo would eventually fall. Tian Dan's immediate task was to eliminate Yue Yi. So, he sent people to Yan to incite officials who were at odds with Yue Yi, spreading rumors against him. Sure enough, an official said to King Hui of Yan, "Yue Yi captured over seventy cities in half a year, but now in three years, he can't even take two cities. He probably intends to declare himself King of Qi." Hearing this, King Hui of Yan removed Yue Yi from his position as general and appointed Qi Jie as the new general. Seeing that the Yan king had indeed fallen for the trick, Tian Dan breathed a long sigh of relief.
Yue Yi originally had great prestige among the Yan army, and when he was suddenly replaced, many officers and soldiers felt resentful. After Qi Jie took command, he immediately ordered the Yan army to surround Jimo in several layers. A few days later, the Yan army heard some civilians say, "General Yue was too kind before; he treated captives well, which is why the people of Qi dared to fight." Others said, "My ancestors' graves are still outside the city—if the Yan army digs them up, what will we do?" When Qi Jie heard these conversations among the nearby civilians, he immediately sent men to cut off their noses and also dug up their ancestral graves. The people inside Jimo were furious upon hearing this, and they urged Tian Dan to lead them out for a decisive battle against Qi Jie. At this point, Tian Dan sent a few men disguised as wealthy residents of Jimo to secretly deliver gold, silver, and treasures to Qi Jie at night, telling him, "The food in Jimo is almost gone, and we will surrender in a few days. When you enter the city, General, please ensure the safety of our families." Qi Jie happily accepted the treasures, thinking to himself, "With no food left in Jimo, how many days can they hold out? I don't need to send troops; in a few days, they'll come begging to surrender!" Thus, he let down his guard and slept soundly at night, feeling at ease.
A few days later, Tian Dan selected over a thousand strong oxen and painted strange patterns on their bodies. Two knives were tied to each ox's horns, and bundles of oil-soaked reeds were fastened to their tails. That night, Tian Dan ordered his men to quickly breach the city wall in over a dozen places, drive the oxen outside, and set their tails on fire. As the flames ignited, the terrified oxen charged madly toward the Yan army camp ahead. Then, five thousand Qi soldiers, wielding large swords, rushed into the enemy camp, while the city's residents beat bronze basins and vessels to create a deafening noise.
At this moment, the Yan army was still sound asleep when they were suddenly jolted awake by earth-shattering shouts and pounding noises. Rushing up with bleary eyes, they saw a blaze of fire and strange, grotesque monsters, filling them with terror. In the ensuing chaos, many Yan soldiers were stabbed to death by the knives tied to the oxen's horns before they could even resist, while countless others were trampled to death by their own comrades in the confusion. Taking advantage of the situation, Tian Dan ordered a swift counterattack, and the Qi army fought with all their might. Those Yan soldiers who managed to survive tried to flee in their chariots, only to be surrounded and killed by the Qi forces, securing a great victory. It was Tian Dan's ingenious scheme of the fire-ox formation that saved the state of Qi from the brink of annihilation.
In 279 BC, Tian Dan defeated the armies of Yan and other states, recovering over seventy cities that had been seized from the State of Qi. At that time, King Min of Qi had been killed by enemy forces, and Tian Dan found King Min's son, Tian Fazhang, who had been hiding among the common people to escape danger, and installed him as the new ruler—this was King Xiang of Qi in history. After King Xiang ascended the throne, Tian Dan was appointed as Prime Minister. Later, King Xiang also entrusted Tian Dan with command of the entire military of Qi, and Tian Dan intensified the training and reorganization of the army, gradually making Qi stronger and more prosperous.