For Liu Heima, losing Chengdu City is acceptable, but Yunding City cannot be lost. If Genting City is still in hand, Chengdu can still hold on. However, once Yunding City was occupied by the Perak Army, the Mongolian army could no longer gain a foothold in western Sichuan and had to abandon Chengdu. If you stick to Chengdu, you will be in a situation where you will be attacked from both sides. Under his desperate urging, the Mongolian soldiers hurriedly hurriedly braved the scorching sun, and finally entered Chengdu city in the dark. At this time, Zan Wanshou's troops were still blocked in the waterway ten miles outside the south gate, while Le Quan'an and his naval brigade were stepping up efforts to clear the water obstacles in the channel. The Mongolian army sank more than a dozen large ships loaded with stones here, which was very troublesome to clean up. It would take two days to dredge the channel.
When it was dark, the field division of the Perak Army had set up camp more than 20 miles outside the west gate of Chengdu. Cao Ergou kept in mind Ouyang Xuan's advice that when dealing with the Mongolian army in the field, he must "strengthen the stronghold and fight a dull battle" and must not fight wastefully, so he was not in a hurry to catch up. He planned to leave for Chengdu early tomorrow morning and work together with Zan Wanshou's troops to attack the city. According to the report of the reconnaissance cavalry, only the infantry followed Liu Heima back to Chengdu City. However, the cavalry led by Hu Du did not enter the city, but went to Yunding City overnight. Cao Ergou's first reaction when he heard the news was to let the cavalry brigade go to Yunding City, but he gave up the idea after thinking about it for a while. This may be the Mongolian army's plan to take the opportunity to set up an ambush on the road and eat the cavalry brigade, or take advantage of the cavalry brigade to attack Yunding City while attacking the infantry of the field division on the way.
Liu Heima sent cavalry to Yunding City overnight, and reinforcements from the Perak Army were also heading to Yunding City at night, but they only took the waterway. In fact, in the Perak Army's combat plan, attacking Chengdu from both land and water was just to attract the attention and strength of the Mongolian army. The real strategic target was Yunding City. Although the two attacking armies of Cao Ergou and Zan Wanshou were strong, they were only partial divisions. The real main force was the special brigade and teaching brigade attacking Yunding City. In order to ensure the completion of the goal, Ouyang Xuante put Huang Dagen in charge of the attack on Yunding City, while he led the staff to sit in Sandushui to coordinate the three-way military operation.
As early as half a year ago, Ouyang Xuan ordered people to conduct a detailed reconnaissance of the route to Yunding City, and formulated a combat plan before the battle of Jiading. There are 500 new auxiliary troops stationed on the mountain of Yunding City, and 500 cavalry stationed at the foot of the mountain. Although they seem to have a small number of troops, they are difficult to capture. Even a field division with strong firepower cannot capture it in a short time. Yunding Mountain City is known as the "Eight Pillars in Sichuan", and its precipitousness is not much worse than that of Diaoyu City. It was not captured by the Mongolian army, but the defenders surrendered due to lack of food. After Liu Heima took over Yunding City, he equipped the defenders with many artillery pieces. Although the range and power of these imitation artillery are far inferior to those of the Perak Army's artillery, they are protected by fortresses and are located at a commanding height, so they can fight back and forth with the Perak Army's artillery.
If a forceful attack failed, the only option was a surprise attack. Therefore, the general staff formulated a battle plan to attack the east and west and cross the sea, and the elite special brigade sneaked into the vicinity of Yunding City in batches to hide. When the Perak Army attacked Chengdu by land and water, Liu Heima would definitely dispatch highly mobile cavalry to rescue him, and the elite special brigade could take advantage of the opportunity to attack at night. At the same time, the main force of the special brigade and the teaching brigade moved down the river from Guankou Village to capture Jintang County, and then went south along the inner river, the Tuojiang River, to Yunding City. When Yu Jie and the Ran brothers selected the site of Kangmeng Mountain City, in addition to considering the steep terrain and ease of defense, they also paid more attention to convenient transportation. At the foot of Yunding City is the Tuojiang River. With the developed waterways, Yunding City can be traced north to Hanzhou, Pengzhou and even Mianzhou, and southward along the water to Jianzhou, Zizhou and Luzhou.
This military operation highlighted the importance of Guankou Village, and also proved that Ouyang Xuan's decision to vigorously manage Guankou Village and surrounding areas was correct, despite all opinions. Guankou Village is not only the choke point from western Sichuan to Weimao, but also the upper reaches of most rivers in the western Sichuan Plain. After the Minjiang River flows out of the mountains, it branches into several rivers and flows eastwards. In addition to the main stream Jinma River, there are also large and small rivers such as Jinjiang River that flows through Chengdu, Qingbai River and Pihe River that flows to Jintang. Next to Guankou Village Daojiang County got its name from this. Although these side rivers are far inferior to the main river of the Minjiang River and cannot allow the Pili Army's gunboats to come and go freely, the river surface is also very wide during the summer high water season, which is more than enough for the navy's warships.
Just when Zan Wanshou and Le Quan'an were attacking Guangdu, Huang Dagen also led his army to set off. According to the plan, Huang Dagen will lead the fleet to capture Jintang from Guankou Village along the Pihe River, and then go all the way to the navy dock in Yunding City. Following Dong Hu's departure were 1,500 people from the teaching brigade and 1,200 people from the special brigade - the remaining 300 people followed Dong Hu, as well as 2,000 basic militiamen and more than 300 large and small ships. A few of these ships were built by the Pili Army Shipyard, and most were handed over to the Mongolian Army. Therefore, most of them were light warships and transport ships, and there was not a single gunboat. However, the Mongolian navy was continuously defeated in Pengshan City, and its water force on the Tuojiang River was also extremely weak and was no longer enough to pose a threat to the Perak Army.
A few days before the Perak Navy troops dispatched from Pengshan, Dong Hu led three companies of soldiers from the special brigade to infiltrate Yunding City in a team of ten. Their route to Yunding City was also divided into water and land. The water route was Huang Dagen's march route, while the land route started from Pengshan and took the trails in the hilly areas of Guangdu and Lingquan counties. The special brigade teams in this operation are all light infantry, but their combat effectiveness is not weak. Each team can fight independently, with one small cannon equipped with one gunner and two ammunition carriers; one archer equipped with a poison crossbow and a short bow; one sniper equipped with a high-precision musket; and the remaining five people They are melee infantry, equipped with spears, swords and shields. All team members carried at least ten grenades.
Yunding City is far away from Chongqing Mansion, a full two hundred miles away. In order to carry as many grenades and other ammunition and weapons as possible, the soldiers of the special brigade who infiltrated this time only brought ten days of dry food. The dry food consisted of honey, salt, flour and fat meat. It is a mixture of foam and other ingredients. It is small in size but very resistant to hunger. In addition, with wild vegetables everywhere in summer, it can meet the needs of high-intensity marching and combat. Since the early reconnaissance operations had already identified the Mongolian army's checkpoints and patrol routes, and the infiltration routes were mostly remote and secluded, the infiltration operation was quite smooth. Of the 273 soldiers from the three companies who arrived at the assembly point, only about 20 were left behind either due to encounters with the Mongolian army or due to injuries or injuries. Mutual reconnaissance operations between the Perak Army and the Mongolian Army were very frequent. In the eyes of the Mongolian Army, these small-scale encounters were just routine reconnaissance operations by the Perak Army. They never expected that such a small number of people would dare to attack Yunding City.
As soon as the Battle of Chengdu started, Liu Heima indeed transferred the Mongolian cavalry stationed at the foot of Yunding Mountain. As soon as these Mongolian troops left, Dong Hu launched a night attack on Yunding City. Although Yunding City's new auxiliary army consisted of 500 people and could be considered elite, they were defeated by the surprise attack of nearly 300 special brigade soldiers, and the battle became one-sided. In addition to the powerful combat capabilities of the Perak Army's special forces and the power of their firearms, the Perak Army also had the construction plans of Yunding City brought by Ran Zhong from Bozhou and detailed early reconnaissance. Of course, the main reason was the insensitivity and carelessness of the new annexed army, which led to the disaster. Most people were captured in their sleep, and the few who resisted had their heads removed.
