In the late Southern Song Dynasty, Mongolian soldiers were divided into three roads. Xixia and Jin Dynasties perished one after another, and the Southern Song Dynasty was in danger. At that time, if you want to protect the Southern Song Dynasty, you must protect Sichuan. To protect Sichuan, we must protect Chongqing; If you want to protect Chongqing, you must keep Hechuan; If you want to keep Hechuan, you must keep Fishing Mountain.

1240, Sichuan deputy envoy Peng Daya sent Gan Run to build a village on the fishing mountain in Dongzhili, Hezhou, to fight against the Mongolian army. 1243, Yu Jie, the special envoy of Sichuan Province, ordered the Ranjin and Ranpu brothers to take charge of the construction of the fishing city, moved the State Administration Office here, and sent heavy troops to control the Jialing River.

1254, Wang Jian was appointed as the commander of Hezhou and began to build fortified cities on a large scale. People from southern Shaanxi and northern Sichuan moved here one after another, and the fishing town became a military center to resist the Mongols entering Sichuan. 1July 258, Genghis Khan's son Meng led 40,000 soldiers, with a number of100,000, and attacked Sichuan from Liupanshan. 12, captured most counties in western Sichuan and northern Sichuan, arrived at Vu Thang Mountain, and prepared to attack Hezhou. Yujie was moved to Fishing City by Song Dynasty.

Fishing City is located at the top of Fishing Mountain, five kilometers east of Hechuan District, Chongqing, with a relative height of about 300 meters. Located at the intersection of Jialing River, Qujiang River and Fujiang River, it is surrounded by water on the south, north and west, and the barrier covers the river. Stone walls with a height of tens of feet are built around the city, and a wall is built in the north and south to extend to the river. There are thirteen large and small ponds and 92 wells in the city, which can be described as sufficient drinking water.

There are naval docks and warships along the river, which can control the three rivers in the upper part and shield Chongqing in the lower part. It is a defensive fortress that supports the war situation in Sichuan, and the terrain is very dangerous. Meng Ge sent general Jin to the fishing city to surrender and was killed by Wang Jian. In the first month of nine years, Mongo Khan relied on his soldiers to make Mazhuang stronger. He quickly avoided the fortified city and made a detour to the east. Regardless of the unfavorable weather and geography, he is determined to capture the fishing city.

So he sent the first king to attack Yili Mountain City, dragged Tu Luxiong to attack Liangshan Mountain City, and ordered Yang Dayuan, commander of the Song Dynasty, to lead an army to raid the old city of Hezhou and cut off the connection between the peripheral cities and the fishing city. At the same time, Niu Lin, commander-in-chief of Sichuan, built a pontoon bridge from Chengdu to Shilin and Fuzhou, cutting off the Song and Yuan Dynasties. But in Tongluo Gorge, it was dangerous, which blocked the northward advance of Song Jun in Chongqing. On February 2nd, Mongo Khan led an army across the Chicken Feet Beach and stationed in Lion Mountain in the east of the city. On the 3rd, Mongo personally supervised the attack on Fishing City.