Zhao Yu had something else to do, and the envoy who persuaded him to surrender reported that the prefect of Xuyi had a tough attitude and refused to open the city to welcome the surrender. In the afternoon, Batu went to persuade him in person, but there was no result at the moment. He didn't say anything, he felt that he still had to base himself on fighting, and unfolded the city map drawn by the scout and looked at it. The city of Xuyi was repeatedly destroyed in wars and rebuilt many times.

Zhao Yu knew that the most recent large-scale reconstruction was during the Shaoxing period of this dynasty, and it had been a hundred years. He looked at the regulation of the city, far exceeding the scale of a county at that time, slightly like the regulation of Hangzhou, Run and other state capitals, according to the danger of mountains and rivers, is opposite to the city of Sizhou on the opposite bank, in line with the status of a military town. At this time, the city was built by Zhang Jun, one of the four generals of Zhongxing, when the Jianghuai war was tight, and the Song court appointed him to guard Xuyi. He set up a tent on the first hill so that he could climb high and look into the distance, overlooking Sizhou, and when he saw the dilapidated old city wall, which had been badly damaged by the war, he decided to rebuild the Xuyi city wall.

The newly built city wall is twenty-seven miles in circumference, facing mountains on three sides and water on the other. According to the topography, the west side of the city stands along the Huai bank, which is majestic and tall; The south, east and north follow the steep slopes of the mountainside, winding and twisting. The surrounding Shanggui Mountain, Taizi Mountain, Qingfeng Mountain, Dongshan, Ershan, and Xiangshan are all surrounded within the city wall, and the first mountain, Fengpoling, Banbian Mountain, Cishi Mountain, and the streets and alleys of the city are all in the city.

In order to ensure the strength of the city wall, the base of the city wall was made of huge stone blocks, lime and glutinous rice juice were used as a binder, and then a rammed earth wall was built on the stone foundation. Where there is a col, reserve drainage channels to prevent water accumulation in the rain. Every other mile, build a circular "flint" or arc-shaped "horse face", because the city wall is rammed earth structure, it is impossible to adopt a rectangular horse face, so the arc shape is adopted.

In Zhao Yu's view, it is very innovative, this kind of enemy platform is conducive to construction and ensuring solidity, because of the earth-moving and set up bluestone ridges, which is not only convenient for taking soil and transporting, but also forms a stepped attack and defense. You can also observe left and right, and defend against enemies on both sides. And the horse face, the flint, and the sentry tower are integrated, which can not only look out and observe the enemy's situation, but also burn wolf smoke to inform the enemy's situation, and can also garrison troops for defense.

On the inner side of the city wall, there is a "horse race" with a width of 5 to 10 zhang to accommodate mobile troop transportation. Finally, the outer side of the rammed earth wall was covered with wall bricks, which from the outside looked like a brick city. And along the Huai city wall, all use huge strips of stone as the wall base, and build the wall with large pieces of city bricks, and the wall is more than three zhang high. In addition, on the Liang Mountain in the north of the two mountains, there is also a "horse race" and "ancient city wall" that surrounds the whole mountain range, more than five miles back in the week, it is rumored that the great poet of the Tang Dynasty Gao Shi was appointed by Huainan Jiedu to crusade against the Anshi rebels, and built the "long siege city" in the second year of Zhide.

At the same time, there are six city gates: the east gate is Xuanhua Gate, the west gate is called the glass gate, the south gate is called the big south gate, the northwest gate is called the water gate and is called the Yongbian gate, the Huaibian gate, the northeast gate is called the Cishi gate, and the southwest gate is called the Baoji gate. In addition, there is a small south gate in the west of the big south gate. From the north gate from the northwest to the west, all mountains are steep, close to Huaishui, or according to the condescending, the shape is dangerous, overlooking Huaisi, and it is clear in sight. Its east gate to the south of the southeast gate, although there is no danger of blocking the water, but the slope valley outside the city is one or twenty zhang or more than thirty zhang wide, the cliffs and rocks are uneven, can not be ridden, can not gallop in vain, seems to be like a natural danger. Only from the east gate to the east of about three miles long, outside the city slope flat wide.

After Shaoxing negotiated peace, Song and Jin "drew Huai as the boundary", Xuyi is located in Huainan, across the Huai River, is the Jin jurisdiction of Sizhou, Xuyi is at the forefront of the Song and Jin war. At the same time, according to the provisions of the "Shaoxing Peace Conference", the Song Dynasty had to pay 200,000 taels of silver and 200,000 horses of silk to the Jin State every year, so the "Year Coin Treasury" was built in Xuyi Baoji Mountain to store the silver silk, and the silver silk was transported to Xuyi in various parts of the Song Dynasty, and it was sent to Sizhou on the other side of the river in the spring of the second year.

Although the peace talks were peaceful for a while, the Jin State and the Puppet Qi often sent troops and horses to cross the river to invade, plunder the border people, and even capture Zhenzhou, Shanyang, Chuzhou and other places. The Song Dynasty launched two northern expeditions of Longxing and Kaixi, and fought with the Jin soldiers in the area of Xuyi and Sizhou.

Later, the officials of the pastoral guard were careful not to build cities, increase troops or conduct exercises on the border in accordance with the provisions of the "Jiading Peace Conference", so that the city fortifications had long been abandoned, and it was not until Ge Hong was appointed as the governor of the army that the city defense could be repaired again. However, the strong city in the later period still did not block the invasion of Meng Yuan, and although the city defense of Xuyi City in disrepair after falling into the hands of the enemy was not repaired, the main body still remained intact, and it was still an insurmountable obstacle for the Song army that lacked heavy weapons in the short term.

How to quickly conquer this fortified city, Zhao Yu first discharged a strong attack, he couldn't afford huge casualties at all, and the city foundation was built with huge stones, not to mention the current black powder, even the TNT in the future life can hardly guarantee the success of the blasting. And the enemy defenders in the city know that they are outnumbered, and they will not go out of the city to fight, and it is not easy to lure the enemy out and annihilate, and the only way left is to take it by skill.

It is difficult to accurately see the flaws in the city defense from the map, so Zhao Yu decided to go by himself. So he called Tan Fei and led a team of guards to quietly go out of the camp and go to the city, and they galloped all the way to the bottom of the mountain in the east of the city, abandoned their horses and walked up the mountain instead, and did not stop until the peak. At this time, the sun has turned west, the city of Sizhou on the other side is bathed in the sunset, the water of the Huai River rolling east is also reflected in the sunset, and the majestic Xuyi City is under the feet.

Their location and the city can be said to be close at hand, even with the naked eye, you can see the figure of the enemy soldiers on the head of the city, Tan Fei is very nervous, if the enemy discovers and sends troops from the city to encircle and suppress, they are likely to be blocked on the mountain. In addition to setting up guard posts, surveillance posts were also dispatched in the direction of the city gate in order to detect the enemy situation in time and give early warning.

"Tan Fei, if you are asked to defend the city with 4,000 troops, how will you arrange it!" Zhao Yu held the telescope and carefully observed it from far and near, and after a while he put it down, raised his finger and pointed to Chengchi and asked Tan Feidao beside him.

"The city wall of Xuyi is long, but the troops are insufficient, and the troops are evenly divided to defend, and the troops are insufficient to resist the enemy's heavy attack. The north of the city is near the river, there is a big river as the moat, the city is thick, and it is difficult to conquer without the help of the naval army; There are mountains on the other three sides, not only the roads are difficult to travel, but also the troops are difficult to deploy, even if they are temporarily broken through, it is difficult for the follow-up troops to keep up, so there is no cause for concern; Only outside the east gate can be used to attack the city. Therefore, if it is subordinate to defend the city, it can only concentrate the use of troops, and the main force is arranged at the east gate, leaving a small number of troops as mobile forces. Set up guard posts in the rest of the places, and if the enemy army is attacking, give timely warning, immediately mobilize mobile forces to drive the enemy! Tan Fei thought for a moment and said.

"If we defend the city, we will concentrate our forces in the long encirclement of the city, so that a small number of troops can take advantage of the danger to defend for a long time, consume the strength of the enemy, and when reinforcements arrive, we can immediately turn the tables. Instead of gradually depleting the forces on the city, and eventually the jade was burned. Zhao Yu said.

"I'm afraid that there are few people in the world who are as bold as Your Majesty, who dare to abandon the high city and deep trenches, and only defend the dangerous place as a evidence." Tan Fei was stunned when he heard this, and immediately understood that in the case of insufficient troops, he could give up the long front and choose a dangerous place to defend it, so that he could give full play to the maximum combat power of his limited forces, so that the enemy army could not fully control the city. But he also knew that even if someone thought of it, no one would dare to do it, because it seemed too risky, and replied with a smile.

"Fortunately, they didn't dare to take risks and survive in death, otherwise we would have to sigh in vain!" Zhao Yu said.

"So Your Majesty wants to use a partial division to feint and mobilize the enemy's troops, and then break the city with the main force?" Tan Fei asked.

"I ask you again, if you were an ordinary soldier in the city, how would you feel at this moment?" Zhao Yu did not answer, but asked rhetorically.

"If your subordinates are a soldier in the city, you want the enemy to conquer Yangzhou City and defeat tens of thousands of your own troops in a row. Coupled with the huge disparity in the strength of the two sides, at this moment, a group of rabble trapped in the lonely city is naturally frightened, like a frightened bird. Tan Fei thought about it and replied.

"Frightened Bird! It's an apt analogy, but what would happen to them if we let loose an arrow at night? Zhao Yu asked again.

"Naturally, I am in a hurry to run for my life!" Tan Fei replied without thinking. He seemed to think of something, but he couldn't catch the flash of inspiration for a while.

"I thought that this high city and deep moat were unattainable for ordinary people, but it was not insurmountable for those who were good at climbing!" Zhao Hao smiled.

"The subordinates understand, just select an elite army, sneak into the city at night, and then create chaos, and then take advantage of the chaos to seize the city gate and enlarge the army into the city!" Tan Fei finally figured it out and said excitedly. He knew that there were many talented people in the guard camp alone, and it would be easy for them to sneak over the city walls, and it would not be possible to take the city, but it would be a piece of cake to create some chaos.

"Not bad! The spies who have infiltrated the city have spread the word that they are ready to receive the army into the city. As soon as they receive our signals, they will cooperate with the operation, create chaos in the city, cause riots, and cover our actions. Zhao Hao only said his plan at this time.

Later, Zhao Yu approached to reconnoitre, looking for weak points that were convenient for the defense of the city and places that were convenient for concealment and climbing, and marked them on the map one by one, and quietly returned to the camp after dark. Before they could sit down, Batu came to ask for a meeting, and Zhao Hao knew that the result of the negotiation was not good when he looked at his face. As soon as he asked, the other party still refused to surrender, and scolded Batu so that he was not depressed, and he felt that it was humiliating to not complete the task.

Zhao Hao could only comfort him with kind words, and left him to eat together, asking him not to worry, he could break the city tomorrow, and he could repay today's humiliation...... 8)