At the same time that Tuhuan was plotting to seize the military and political power of Yangzhou City, the Song army had moved forward with the army and camped five miles away from the city. From time to time, there will be arguments in the emperor's imperial tent, and the guards will set up a cordon outside the imperial tent, prohibiting everyone from approaching, even the matter of serving tea and pouring water is also served by Ouchi Governor Wang De, obviously this is an extremely secret meeting.

"Your Majesty, my subordinates thought that after the army of Mengyuan invaded the south from Gaoyou, they should go south along the canal and make a gesture of galloping to aid Yangzhou. After arriving in Jiangdu, it suddenly turned east to bypass Taizhou, which was occupied by our army, drove directly to Taixing, and then set up a pontoon bridge at the mouth of the Mohe River to cross the river, this route has the shortest distance, and it can appear in the south of the Yangtze River unexpectedly! Ying Xi pointed to the sand table and said.

At present, our naval army has advanced to Shaobo Town, and the Marine Brigade has also controlled the crossing along the river, so the subordinates thought that the enemy who invaded south would avoid the canal and march, take Gaoyi Avenue, and cross the Guyan River in Yiling Town. In this way, the connection between our army battalion and Taizhou can be divided, and the situation of rescuing Yangzhou is also made, and then it suddenly turns to Taixing in the east. Chen Fenglin shook his head and gestured on the sand table.

"Chen Dutong, if Meng Yuan goes to Yiling Town, it is true that he can divide the connection between Daying and Taizhou, but it is also under our attack, isn't he afraid that we will block the southbound passage?" Ying Xi waved his hand and insisted on his opinion.

"Well, that's right. So what does Chen all think? Zhao Hao touched his chin and twisted his face and asked.

"The subordinates insisted that this would be the case, and the enemy army was the main force of the cavalry, and they only needed to leave part of their forces to entangle with us, and they would be able to pass quickly. And they chose this road to march to cover up their intention to invade the south and take advantage of the situation to change the route. Chen Fenglin said.

"In this way, wouldn't the Mongolian army have exposed their intentions and given us the opportunity and time to warn Jiangnan!" Ying Xi said with a smile.

"Well, that's good. However, intelligence shows that in order to speed up the march, the southbound Mongolian army only prepared food and grass for ten days, and only by crossing the river and capturing Changzhou as quickly as possible could it obtain supplies and continue to move south. Chen Fenglin frowned and said a little vaguely.

"It is even more impossible, they want to cross the river from here, opposite Jiangyin, our army has tens of thousands of soldiers here, and it is difficult for them to succeed without the help of the navy. Even if you succeed in crossing the river by luck, the city of Changzhou is strong, and it is not possible to complete it in a short period of time if you want to conquer it, and if it lasts for a long time, it will be besieged by reinforcements from various departments, and it will not be able to achieve its goal of invasion of the south. Tan Fei interjected at this time.

"Commander Tan is right, the Mengyuan army will not go along the canal if it invades south, otherwise it will be difficult to get enough food and forage!" At this time, Ni Liang said.

"Ni Dutong, the Mongolian soldiers are all driving cattle and sheep together, as a supply on the way, how can there be a risk of food and grass!" Ying Xi smiled and waved his hand.

"In charge, have you ever heard Your Majesty say that after the Mongols enter the Central Plains, not only will their living habits gradually change, but they will also make adjustments to march and fight, but if they can't accept it, it will lead to the combat effectiveness being burdened by logistics, leading to a decline in combat effectiveness, and they will eventually be defeated by us!" Ni Liang was very surprised that he could say such a thing, and twisted his face to speak.

"Your Majesty is new to Qiongzhou when he said these words, and it is normal that the principal has not heard of it!" Seeing Ying Xi's confused look, Chen Fenglin pulled Ni Liang and said.

"Then it's no wonder, but these have been compiled into a book for the generals to study, and they should be read at their leisure!" Ni Liang said with a smile.

"Then where does Ni Dutong think that the enemy of the southern invasion will go?" Ying Xi was still a little unconvinced, knowing that the little emperor was still a student of his father, so he asked rhetorically.

"I thought Yuxi Timur would go like this!" Ni Liang drew a route on the sand table.

"How is it possible, such an enemy army has to walk half the distance, and it will make it more difficult for them to supply on the way!" Ying Xi pursed his lips and said loudly.

"What Ni Liang said is the most likely!" Zhao Hao, who was on the side, said with a smile. He came with the memory of his previous life, and of course he knew that the reason why the Mongol army was invincible, in addition to being the king of cavalry and archery, as a nomadic Mongols, the fundamental reason why they were able to carry out such a long-distance high-speed expedition was that the Mongol army lived as a herdsman, and the structure of the entire Mongol army, so that they could always rely on strong mobility to appear in unexpected places for the enemy.

During the Mongol army's conquests, domestic animals often marched with the army on a large scale. Whether they are horses, camels, cattle and sheep, these domestic animals are actually very important tools for production. In particular, horses and camels were not only used for warfare and carrying goods, but most importantly, they were also often the source of some of the necessities of life for the Mongol soldiers.

When the Mongol soldiers went out on battle, they would carry a multi-horse with each person, and these horses were not only used to change horses during battle, but also milk products made from the mare's milk were also an important source of food for the Mongol soldiers. In addition, horsetails and horsehair can also be used to make ropes. Livestock manure is a very important source of fuel, and it can be said that it can be used to the fullest.

Of course, carrying livestock alone is not enough to solve all the problems. In particular, the large number of horses, camels, cattle, sheep and other livestock that accompanied the advance of the Mongol army naturally required a large amount of forage and fresh water. As a result, the Mongol army's march and conquest often had to rely on abundant pastures to support it.

For this reason, the Mongol armies generally sent small units of cavalry before they were launched, or relied on merchants to gather information to ensure that the army's livestock would not suffer serious losses due to insufficient food and water. If we compare the Mongol expedition to the west with the migration routes of other nomadic peoples, we will find that there is a striking overlap between the two, and the dependence of the Mongol march on pasture can be seen.

During the Mongol conquest of the Middle East, the Mongols consciously destroyed the irrigation system of the local farmland. On the one hand, this was to break up the local resistance ability, and another important reason was to force the farmland to be abandoned, so that the Mongols could convert it into pasture for the marching army.

However, this rather "immoral" approach was also used in the early days of the conquest of the Central Plains, but it did not always work. In the Jordan Valley, Hulegu withdrew the main force and left only a cowardly detachment, largely because the pastures in the Jordan Valley were not enough to maintain the large herds of the Mongol army. The Mongol defeat at the Battle of Ain Jalu was largely due to the fact that the pastures in the Jordan Valley were not sufficient to sustain the Mongols' large army.

However, the Mongols did not fail to consider the problem of limited pastures. In the Middle East and south of the Great Wall of China, where the terrain is relatively complex and densely populated, the Mongols' habitual reliance on herds is often ineffective. Correspondingly, the Mongols had to solve the logistical problems caused by the lack of pastures by establishing local administrative means and by taxing the conquered areas.

To sum up, the Mongolian cavalry in the era of Mongol conquest was intimidating, in addition to their fierce combat effectiveness, the characteristics of logistics and supplies also determined their combat scope and combat effectiveness maintenance methods, which were difficult for Eurasian countries to fight against at that time. It is precisely because of this that the Mongols were able to complete such an astonishing expansion and conquest. Or, if the Mongolian iron cavalry moves, it is really invincible in the world, so it destroys one civilization after another, but they can't always move......

"It's still Ni Dutong who got the moon first near the water building, and after being carefully taught by His Majesty, he can see the Tao at a glance!" Chen Fenglin arched his hand to Ni Liang and said, "The current enemy we are facing has been in Tuntian on both sides of the Huai River for many years and has given up the nomadic life. Now the ox is used to plough the field, and it is more precious than us, how can we be willing to kill it to make dry food, or go to war with the army as a supply. The flock, on the other hand, will eat the crops and will not shepherd on a large scale. How could they collect so many cattle and sheep on the road in such a short period of time? ”

"Well, Ni Dutong is exactly what he said." Tan Fei also said thoughtfully, "Yuxi Timur mobilized 100,000 troops for this southward migration, and the war horses will also be multiples, they can only choose to march away from the land of Tuntian, but it is estimated that a partial division will be sent to Yangzhou with great fanfare, so as to paralyze our army." And they circumnavigated Taizhou, because the land east of the Ruhai Canal was close to the sea, suffered from saline erosion and was not suitable for farming, and there was no large-scale tuntian, so the land was barren and overgrown with weeds, which had always been used for grazing horses. And there were many salt pans along the way, forming many market towns, from which they could get food supplies, and they did not need to use the supplies they carried, which were used after crossing the river. ”

"And where do you think they're going to cross the river?" Regarding the analysis of the two, Zhao Yu agreed, nodded and asked again.

"The subordinates thought that Yuxi Timur would choose to cross the river in Jiangkou Town, Tongzhou, where the water surface is narrow, and in the dry season, it is very suitable to carry boats or erect pontoon bridges. And on the opposite side, we had very few troops stationed, only a few forts as early warnings, and they were unable to resist the crossing of the river by the army. At the same time, Jiangkou Town, which was close to Jingzhou and Li Feng Jian, could serve as a cover for their assembly, and it was also convenient to mobilize servants and requisition ships to assist them in crossing the river. Tan Fei pointed to the explanation of the route drawn by Ni Liang on the sand table, but his face suddenly changed, "It's broken......"

"What's wrong?" Chen Fenglin was taken aback by his surprise and asked urgently.

"It's only a hundred miles away from Changshu, and if you force the army, it only takes one day!" Tan Fei nodded on the sand table and said to Changshu.

"Your Majesty......" Several people also changed color when they heard this, and looked at the little emperor in surprise.

"Exactly, the enemies we are facing are not all fools, Yuxi Timur is our current fierce enemy!" Zhao Hao rubbed his chin vigorously, but his face was calm, as if all this had been expected by him.

"I didn't expect that the reason for this is that the attack on Changzhou is fake, and the capture of Changshu is true!" Ying Xi was not calm anymore, and kept shaking his head. The information they received from the spies of the bureau said that Yuxi Timur wanted to seize Changzhou to obtain supplies, and then waved his army to continue south.

"If Changshu is lost, it will be difficult to trap them!" Ni Liang also frowned.

Although Changzhou and Changshu are only one word apart, they are thousands of miles apart. Changshu is bordered by the Yangtze River in the northeast, Taicang in the southeast, Kunshan and Pingjiang in the south, Jiangyin and Wuxi in the west, with convenient waterway transportation. After recovering Jiangnan, Zhao Yu formed a defense line on the Yangtze River and set up a series of material transfer stations in depth to facilitate the supply of the front. Changshu is located at the hub and is also a major grain producing area, so it was chosen as a place to hoard supplies.

However, Changshu has always been only a county seat, although there is a city wall in the Western Jin Dynasty, but it was not until Song Jianyan that a moat was built, and it has the rudimentary shape of the city. But it is still a city circumference of only more than 130 zhang, the city wall is only one zhang high, four feet thick, the bamboo and wood are the fence, and there is no building to build the small city. This kind of city wall is completely defenseless, and in fact, it can only be regarded as a large courtyard wall without attached fortifications.

After Changshu was selected as a transit place for supplies, the city was expanded. However, according to the regulations, in addition to the capital and state capital units in the Song Dynasty, the county-level city walls were mostly at the level of 10 to 15 feet, and some city walls were less than 10 feet, such walls had narrow tops, low battlements or no battlements at all. Relying on the city wall itself, there is basically no defensive ability, and most of them rely on the auxiliary fortifications of the city wall, such as war sheds, to raise the city wall and build combat platforms.

But this expansion is also in accordance with the highest regulations of the county to build, the city wall is fifteen feet high, the battlements are three feet seven inches thick and two feet thick, the bottom of the city wall is twelve feet wide, and the top is five feet wide, but the city wall is still a rammed earth city, and there is no brick, but this is already a county-level city wall in the Song Dynasty. In order to hoard supplies, the city was expanded to include Yushan outside the city. And Changshu was originally a water town, the waterways in the city were crisscrossed like a network, and the shipping was developed at that time, and then the water city gate was set up to facilitate the transportation of materials.

After a series of transformations, Changshu City still has the problem of poor city defense facilities, so it can only rely on the auxiliary fortifications of the city wall such as war sheds for defensive operations. However, in the era when the besieging side lacked trebuchets and other siege equipment with a low technical level and lacked the ability to attack the city, it can be said that it was quite effective in defense.

Of course, this kind of combined city fortifications are mainly cost-effective, and the ancillary fortifications such as the war shed can be disassembled and stored in peacetime, and the city walls and battlements are low and narrow, which can save a lot of city wall construction costs and daily maintenance costs, and the local government cannot fight against the central forbidden army with trebuchets according to the city, which is also in line with the national conditions. But who would have thought that Changshu City, which was located in the rear, would become the focus of this battle......