In "Water Margin", Zengtou City is located in the southwest of Lingzhou, the hinterland of Shandong, and in the original text, he came to Zengtou City in the southwest of Lingzhou unexpectedly, and was taken away by the five tigers of the Zeng family. Zeng Tou City violated the bottom line of Liangshan twice in a row, snatched Liangshan horses, and shot Chao Gai to death in the middle. When Zengtou City captured Liangshan's horses for the second time, Song Jiang couldn't hold his breath and was determined to take revenge and attack Zengtou City.
Zengtou City is located in Yuncheng County, Shandong, not far from Liangshan. There are a total of seven fierce generals there, in addition to the five sons of the chief who are known as the "Five Tigers of the Zeng Family", there are also two sect leaders: Shi Wengong and Su Ding, of which Shi Wengong is very strong. In addition, Zengtou City has more than 10,000 soldiers and horses, and its influence is very large.
Liangshan's first attack on Zengtou City was because Duan Jingzhu stole the Zhaoye Jade Lion and originally wanted to give it to Song Jiang, but it was robbed by the five tigers of the Zeng family and became Shi Wengong's mount. So Chao Gai led his troops to attack, but during the battle, he was hit by Shi Wengong** in the cheek, and he died soon after because the arrow was poisonous.
Since then, Zengtou City, especially Shi Wengong, has become Liangshan's sworn enemy. The second time was because Duan Jingzhu, Yang Lin, and Shi Yong bought more than 200 horses from the north for Liangshan, but they were taken by strongmen on the way and sent to Zengtou City, and only Duan Jingzhu fled back to Liangshan. So Song Jiang prepared to settle the old accounts and the new accounts together, and attacked Zengtou City again.
In the battle of Song Jiang to fight Zengtou City at night, Liangshan's side first used fire attacks and other tactics to break the trap on the periphery of Zengtou City, and then designed to ambush the Zeng family army who came to sneak attack twice. And Shi Wengong was also captured alive by Lu Junyi when he was defeated and fled, and then his heart was dug out by the people of Liangshan to pay tribute to Chao Gai, which was regarded as a successful revenge for him and made him blind. According to Chao Gai's will to seize Shi Wengong before his death and become the leader of Liang Shanbo, Lu Junyi sat in the second position.
The main reasons for Song Jiang's attack on Zengtou City are as follows:
Revenge for Chao Gai: When Chao Gai attacked Zengtou City, he was hit by Shi Wengong's poisoned arrow and eventually died. Song Jiang, as Chao Gai's friend, naturally wants to avenge Chao Gai.
Turf Fighting: Zengtou City is located near the area where the heroes of Liangshan are active, and is one of their important territories. Song Jiang believed that Zengtou City was the sphere of influence of the heroes of Liangshan, and attacking Zengtou City could expand the territory and sphere of influence of the heroes of Liangshan.
Looting grain, grass and money: Zengtou City is a wealthy place with a lot of grain, grass and money. Song Jiang's attack on Zengtou City could rob these resources to support the daily expenses and war needs of the heroes of Liangshan.
To sum up, there were many reasons for Song Jiang's attack on Zengtou City, including revenge for Chao Gai, fighting for territory, and robbing grain, grass and money.