The military information reported by Baijianu to New Zealand is not entirely accurate. It was indeed Cao Ergou who attacked Jianzhou and Zizhou, and the first division under his command was also the well-deserved first main force of the Thunderbolt army, but there were not 10,000 people. The First Division had two infantry brigades, a naval brigade, a cavalry brigade, and a divisional brigade, all of which totaled 7,500 men. In this campaign, the General Staff transferred a main battalion of the 1st Division Naval Brigade to support the Battle of Zhanwanshou Shenluzhou, while a battalion of the Division Brigade stayed behind in Genting City. The cavalry brigade, which was the absolute main force, did not accompany it, but carried out other important combat missions.

Therefore, Cao Ergou attacked the two states this time, and there were only one part of the naval brigade, the division brigade and two infantry brigades under his command, with a total strength of 5,000 people.

However, it is not wrong to say that there are tens of thousands of people, because there are also 5,000 basic militiamen who transport heavy logistics with them. The combat power of these basic militias is actually not weaker than that of the new annexed army, and it is impossible to mistake to include them in the number of troops, which is why Baijianu mistakenly believes that they are also regular troops. Of course, even if these basic militias do not participate in the war, the combat power of the regular army of the 5,000 Thunderbolts is extremely terrifying. The two infantry brigades have hundreds of large and small artillery pieces, including dozens of powerful new field artillery pieces, and dozens of heavy artillery pieces in the naval brigades. These heavy artillery pieces are the ultimate weapon of this generation, and if they are fired at in a concentrated manner, no city defense facility can resist them.

Just like Niu Lu, Liu Heima also believes that the main force of the Thunderbolt Army has gone to Luzhou by water, and Shenjian City is the battlefield of wrestling between the two sides. This judgment gave him the idea of a sneak attack on Genting City for a while. As long as Genting City is recaptured, it can occupy the strategic initiative, and then slowly map the Chengdu Plain. However, thinking of the steepness of Genting City and the sharpness of the artillery, he gave up the idea of taking risks and turned to focus on the defense of Jianzhou City.

As the front line of the confrontation between the two armies, even if Niu Ling took a large number of elites with him south, there were still 3,000 elite Mongolian and Han soldiers stationed in Jianzhou City. These Mongol Han troops are Liu Heima's last capital and hole cards, and their combat power is equivalent to the combat power of 6,000 new annexed troops. After retreating from Chengdu, in order to prevent the attack of the Thunderbolt army, Liu Heima spent a lot of money to build a city defense system, and also imitated a lot of artillery to secure the city. In his opinion, even if the Thunderbolt army came to attack, it would not be able to take Jianzhou City in a short time, and as long as the reinforcements arrived, the Thunderbolt army besieging the city would be in a dilemma.

Jianzhou City is located in the inner river water, that is, Ouyang Xuan called the Tuojiang River. In order to prevent the attack of the Thunderbolt army and navy upstream, Liu Heima ordered people to set up a water barrier at the shallow point in the river three miles upstream of the city. At this distance, although the heavy artillery of the Thunderbolt army could reach the city wall of Jianzhou, the lethality had been greatly reduced. In fact, the Mongol army tried to build a water barrier further upstream, but was unable to return due to the rapid flow of the river.

After repeated deductions, Liu Heima believed that the artillery warships of the Thunderbolt Army could not pose a threat to Jianzhou City in a short period of time, and he built a lot of anti-artillery fortifications in front of the city wall and in the city, and he held the strong combat strength of the Mongol and Han armies under his command, coupled with the misjudgment of the battle situation, which led to his continuous urging of Niu Ling to go south to Shenjian City.

Although Cao Ergou has a strong personality, he is also a person who plans and then acts. He knew that Liu Heima must be on guard against the naval gunboats, so he waved his army to attack Jianzhou, and the task he assigned to the naval brigade was not to capture the city, but to fight for the right to control the river to ensure the absolute safety of the hundreds of transport ships accompanying him. In addition to carrying grain, grass and baggage, the most important supplies carried by these transports were the artillery of two infantry brigades.

Due to the limited number of ships, the soldiers of the infantry brigade and the divisional brigade of the 1st Division did not take a boat, but moved along the road along the Tuojiang River, which naturally did not hide from the eyes of the Mongolian army. It's just that the Thunderbolt army's marching routes are all under the guns of the warships, and the cavalry under Liu Heima has also been transferred to other battlefields, so they can only watch the Thunderbolt army approach and have no choice.

The ships of the 1st Division docked at the water barrier three miles north of Jianzhou City, while the infantry coming from the coast advanced to two miles from the city and began to set up camp. Taking advantage of the unstable foothold of the Thunderbolt army, Liu Heima sent his son Liu Yuanli to lead the army to raid the Thunderbolt army, which was building a camp, but suffered heavy casualties under the fierce fire of the warship artillery, and had to flee back in embarrassment. In fact, the Perak soldiers who came ashore were already armed with muskets and spears, and lined up in a neat phalanx, closely protecting the backbone militia that had built the barracks, even if the Mongol army rushed over, there was no gap to take advantage of.

Thanks to sharp digging tools, ample iron frames and a large number of sacks, as well as the large number of militiamen, the Perak army camp was completed in only half a day. In the process, Liu Heima ordered people to bombard the Perak army camp with artillery, but found that the imitation artillery did not have enough range and could not shoot at the Perak army camp at all. Although the craftsmen of the Mongolian army tried their best, because they did not master the principle of firearms, coupled with the backward iron-making and gunpowder technology, although their artillery was blessed with the height of the city wall, they could not hit the camp site carefully selected by Cao Ergou. The occasional shells that rolled down were also weak and non-lethal.

After the construction of the camp site was completed, the Perak soldiers pushed the guns of the infantry brigade off the ship. The simplest and crudest way to judge the power of an artillery is to look at the length and caliber of its barrel, generally speaking, the longer the barrel, the farther it will hit, and the larger the caliber, the more powerful it will be. In order to ensure the power of the artillery, the artillery of the infantry brigade is very heavy, the light one is 300 catties, and the heaviest one is even more than 1,000 catties.

With such a large weight, the power of the artillery is naturally not weak. As far as the thousand-pound heavy cannon is concerned, the iron bullets it fired weigh more than ten catties and have a range of four miles; In a 300-kilogram light field battle, its iron bullet weighs four kilograms, and its effective range can reach two and a half miles, which is why the Thunderbolt army set up camp two miles outside Jianzhou City. These big black guys all have iron two-wheeled gun mounts, which are usually towed by mules and horses. This time, in order to save animal power, it was transported by water, and it was very convenient to lay thick wooden planks on the river bank and drag them down directly.

When the heavy artillery deployment of the Thunderbolt Army was completed, it was the time when the city of Jianzhou was broken. Under the concentrated fire of hundreds of artillery, the Jianzhou city gate and suspension bridge were blown to pieces, and the city wall also collapsed several sections under the dense heavy artillery. Liu Heima, who was commanding at the head of the wall, saw that the city defense he had painstakingly managed was destroyed after a few rounds of artillery, and his soldiers were also suffering heavy casualties. Liu Yuanli, who was beside him, was shocked, and hurriedly ordered his soldiers to carry him to the south gate.

This Liu Heima fell ill, and the responsibility of defending the city fell on Yelumaizhu. Seeing that the artillery of the Thunderbolt Army was fierce and the number of people was several times larger, he knew that Jianzhou could no longer be defended, so he implored Liu Yuanli to retreat to Zizhou with the unconscious Liu Heima, and he led people to plug the gap. Now the gates of the city were wide open, and the Thunderbolt soldiers, under the cover of their shields, were pouring towards the gap.

Jerumaizhu was also extremely brave, and he led his men to hide in the gap and fought to the death. Because the barrel of the cannon was hot, and in order to avoid accidental injury, the Thunderbolt artillery had stopped firing, so the battle at the gap became hand-to-hand combat. Although the Thunderbolts had grenades and muskets, the Mongol Han army also had bows and crossbows and grenades - although the effect was far less than that of the Thunderbolts, and there were even Mongolian soldiers who died with gunpowder bags and the Thunderbolt soldiers.

In order to reduce casualties, Cao Ergou had to order the soldiers to retreat, first plough the ground with artillery fire and then attack, and so on many times before the Mongol army in the city was completely annihilated, until it was dark before the Jianzhou City was completely controlled. All beings are equal under the heavy artillery, and although the general who defended the city, Yelumaizhu, was brave, but he also died under the artillery fire, becoming the most eye-catching name in the first division's battle merit book.