The Yuxi Timurid army was annihilated, Jiangnan regained calm, and Lianghuai became the focus of the war. At the same time, the whole pattern also changed, while Meng Yuan was mobilizing the guards to go south, Zhao Yu received information that the Yuan army stationed in Mobei also began to mobilize and prepare to go south. As everyone knows, Mobei is not only the birthplace of the Mongol Empire, but also the birthplace of Mongolia, and also has a large number of core troops with strong combat effectiveness.

According to the intelligence, the Yuan army stationed in Mobei, in addition to the pro-army avant-garde commanded the Asu army and the rest of the guards and horses, the Mongolian army had 10,000 households, and the Harachi army had 19 thousand households. and the king's horses, including the king of Anxi, the horses of the Wangu tribe, and the horses of the Chi Qi Lesi horses. If you know a little about the Mongolian military, you can see that the troops stationed in Mobei in the Yuan Dynasty are not only numerous, but also the elite troops in the Yuan army, and their quality far exceeds that of the guards and Wanhu troops stationed in the Central Plains and Lianghuai regions.

Zhao Yu understood that these Yuan troops had moved south one after another, which had brought great difficulties to the plan he had been secretly planning to advance into the Central Plains, but he thought that this was also an opportunity. The elites of the two countries gathered here for a decisive battle, and if they win, they could go north to the Central Plains; And Meng Yuan lost all his old bottom, not only fell from the world's first military power to a second-rate military country, but also did not have the capital to compete with the Great Song Dynasty, and only by withdrawing from the Central Plains could he survive.

But Zhao Yu also clearly knew that the unification of Chinese dynasties was often the unification of the north to the south, and the unification of the whole country from the south to the north was rarely successful, and as far as he knew, only Zhu Yuanzhang, the Taizu of the Ming Dynasty, had done it. He still remembered that when the monarchs and ministers of the Ming Dynasty were discussing the strategy of the Northern Expedition, the generals mostly advocated taking the capital directly, but Zhu Yuanzhang thought:

Yuan built the capital for a hundred years, and the city must be fortified. If the division is deep, it can't be broken, and it will be under the fortified city, and the salary will not continue, and the reinforcements will be set in four sets, and there will be no battle to enter, and there will be no basis for retreating, which is not my benefit. I want to take Shandong first and remove its shielding; Rotate Henan, break its wings; Batong Pass and guard it, according to its hub. The situation in the world, into my control, and then into the capital of the army, then the other side is alone, without a fight. Both Keqidu, walking in the clouds, Jiuyuan, and Guanlong, can be swept down.

In history, before Zhu Yuanzhang's Northern Expedition, it was based on Jinling, and Chen Youliang in Xiping controlled the upper reaches of Jingxiang; Destroy Zhang Shicheng in the east and consolidate the foundation of Sanwu. The control of Jingxiang ensured the control of the situation on the Yangtze River; The consolidation of Sanwu ensured the stability of the rear. However, after experiencing the impact of Liu Futong's uprising, the Yuan Dynasty was weakly armed, and the generals it relied on to lead the army, such as Timur who encircled Shanxi, Li Siji, Zhang Liangbi, etc., who supported the army, fought for power and profit, each sought to protect the territory and divide the territory, attacked each other, and did not unify with each other. This also happened to give Zhu Yuanzhang the opportunity to break through and smash most of the capital.

Zhao Hao thought that the current situation was not as favorable as Zhu Yuanzhang's Northern Expedition, but the general trend was not bad. He sent Wen Tianxiang west to conquer Sichuan and Shu, even if he could not recover the whole territory, but he also blocked the passage of Meng Yuan from Sichuan and Shu along the river. Moreover, the battle of Jiangdong annihilated Meng Yuantun in Henan and Shandong, and occupied the land of Huainan.

At present, after the Yuan Dynasty lost control of the territory south of the Jianghuai River, it could only rely on Henan and Shandong as southern barriers to resist the Northern Expedition of the Song army. Zhao Yu thought that the strategy of Shandong should be the focus, which is not only the southern barrier of the capital, but also monitors the main artery of north-south waterway transportation, and occupies a pivotal position between the north and the south, so it is advisable to take it first to remove its shield.

Once the Yuan Dynasty lost Shandong, it was equivalent to opening the door, and there was no natural barrier to resist the attack of the Song army. After their own side captures Shandong, they can use the northern section of the Grand Canal to drive down the river. Take Henan to protect your flank. As for the capture of Henan, Zhao Yu also thought that with his comprehensive strength, it was not enough to use troops in Guanzhong, and he should temporarily be on the defensive on the west road to prevent the Yuan army in Guanzhong from going east.

Zhao Yu also understands that in any overall competition, the Central Plains is a place of contention, and that is the real arena for the champion. Only the geographical conditions of the Central Plains extending in all directions can obtain the situation of controlling all directions. If the Central Plains is stable, the Quartet can be stable; If the Central Plains is chaotic, the square will inevitably fall apart. If you don't manage the Central Plains well, you won't be able to win the world; If we do not manage the Central Plains well, we will not be able to seek long-term peace and stability in the world.

However, the Central Plains, which is located in the middle of the world, will also become a place where enemies can be attacked on all sides when the world is in turmoil, and the centrifugal force of the four sides can be enough to tear apart the situation in the Central Plains, and will make the Central Plains a place of turbulent convergence, and the torrent of convergence can wash away any efforts to defend the Central Plains. But at this time, it is easy to rely on the dangerous land of the four corners of the mountains and rivers, but it is difficult to rely on the land of the four wars in the Central Plains.

Therefore, Zhao Yu borrowed the strategy of Zhu Yuanzhang's Northern Expedition to the Central Plains, first captured Shandong, then rotated westward to capture Henan, and then marched to Hebei to attack the capital of Yuan. Most of the capitals have been lowered, and then entered Shanxi, using this as a springboard to march into Guanlong, seize Bashu, and unify the world. The difference is that he is now blooming everywhere, using the tactics of disrupting Yunnan, marching into Sichuan and Shu to contain Meng Yuan's forces, and then attacking the two Huai so that the enemy can not look around, so that Meng Yuan can only passively follow his own rhythm, and lose control of the strategic initiative.

Zhao Yu naturally knows that the shortcomings of his tactics are also obvious. First of all, the use of troops everywhere made the financial pressure very great, so that he could not increase the number of troops indefinitely; However, if you want to spend less money and do more, the battle line will be long and the battle line will be long, resulting in the dispersion of troops, and it will be difficult to implement the tactics of large encirclement and large detours, so you can only use troops cautiously and make up for the lack of physical strength with your brains.

At the moment, Zhao Yu was also enjoying the pain of being cocooned and self-bound, first in order to annihilate the Yuxi Timurid army, he froze outside Yangzhou for several months, and then staged a plan to empty the city with his own danger before he could settle it. And at this moment, it is clear that the Central Plains is close at hand, Bianliang seems to be at his fingertips, but he does not dare to act rashly, he understands that the bold use of troops is not the same as brute force, with the little force in his hands to seize the city can not be defended, but also to risk being besieged. Therefore, the greedy scratched their ears and scratched their cheeks and did not dare to eat, so they could only look at it from afar on the other side.

If he wants to achieve victory on the battlefield and solve the lack of troops, Zhao Yu knows that there is only one way he can use, that is, the so-called 'hurt his ten fingers, it is better to cut off one of his fingers', that is, the great man's tactics of 'concentrating superior forces to fight a war of annihilation'. At present, both sides are transferring troops to the front line, and the battlefield of the decisive battle will be placed in Xuzhou, the hub place.

Xuzhou can be called a place for Chinese soldiers to fight, Zhao Yu had seen a statistic in his previous life, the war that occurred in Xuzhou, only recorded as many as more than 400 times. The earliest one occurred in the twenty-first century B.C., when Peng Boshou conquered the West River; The most recent one, the Huaihai Campaign, one of the three major battles to liberate the country. On average, every ten years or so, Xuzhou will have to fight a war. Even in peacetime, Xuzhou was heavily guarded and set up quite a high-level military command organ, so the place of contention was worthy of its name.

So, why do the soldiers fight for Xuzhou? In fact, it is also because its geographical location is strategically important militarily. Xuzhou has always been the junction of the north and south, in the center of Beijing and Nanjing, is the barrier to defend the tax town in southern Jiangsu, it can be said that the wealth of southern Jiangsu and Xuzhou's barrier role is inseparable. And it is held in the key points of transportation, the north can control the North China Plain, the south can attack the south of the Yangtze River, the west can enter the hinterland of the Central Plains, and the east can have a seaport as a retreat. It is known as the key to the north and the important town of the south!

In the words of the people of Xuzhou, the city they live in is "neither south nor north, neither big nor small". In the eyes of the southern military strategists, occupying Xuzhou is equivalent to getting a key to open the lock of the northern gate; In the eyes of the northern military strategists, the capture of Xuzhou is equivalent to the occupation of the bridgehead for the march to the south. Therefore, the ancients had the saying that "the gains and losses of Pengcheng are the prosperity and decline of the north and the south".

Although this place belongs to the Huanghuai Plain, but the Lunan Mountains extend to this, so the territory of the hills is undulating, surrounded by mountains, and the momentum is like a kettle. In the era of cold weapons, these mountains were like the natural barrier of Xuzhou City, easy to defend and difficult to attack. The rivers outside Xuzhou, and sometimes the Yellow River is often diverted and flows through Xuzhou, which is guarded by the Yellow River, and also has a natural defensive effect.

Moreover, there have been smooth waterways in Xuzhou since ancient times. Before the Southern Song Dynasty, Xuzhou City was surrounded by Surabaya to the north and east, and Bianshui was flowing through it to the west. From Surabaya to the north, you can pass through Jinxiang, Qufu, Dingtao; From Bianshui to the west, you can reach Kaifeng and Luoyang; Go south along Surabaya to Huaiyin. These cities, which could be reached by Xuzhou, were very important at that time, and some were also battlegrounds.

To fight a war, especially a major war, it is necessary to mobilize troops, and the troops must be extremely fast, and military deployment must be completed in the shortest possible time and at the fastest speed. In addition to the transfer of troops, there is also the common sense that "the soldiers and horses have not moved, and the grain and grass go first". Under these conditions, traffic conditions become a key factor. If anyone occupies Xuzhou, there will not be much difficulty in transporting troops, weapons, grain and grass. In addition, the land route is also accessible to all directions, and there have been post stations here for generations, which can quickly transmit news and mobilize troops.

Especially in the Southern Song Dynasty, the Yellow River broke and flowed. After the Yuan Dynasty, Kublai Khan was in power to renovate the Grand Canal, and Surabaya was incorporated into the Beijing-Hangzhou Grand Canal water system, which made Xuzhou's status as a transportation hub to a higher level. At that time, the grain was taken from the lower reaches of the Yangtze River, such as once this major artery on the water was blocked, most of them were waiting to be fed, and the Beijing division was in danger. Xuzhou is the place where this water artery must pass, so it has the reputation of "the thoroughfare of five provinces", leading to Shandong, Hebei and Gyeonggi in the north and Zhejiang in the south.

In addition, Xuzhou is located in the border area of Sulu, Henan and Anhui, and is a regional central city. In the thousand-year history, there has been a long period of prosperity and development. Because of the abundant resources and moderate climate here, "there is land suitable for grain, mountains and forests, beaches and fruits, water and fish", and there is a saying of "abundant adoption of Kyushu". When fighting a war and stationing heavy troops, food and grass are not a problem. Moreover, Xuzhou has always had a relatively large population density and sufficient military resources.