After more than 20 days of emergency construction by 30,000 soldiers, the pass of the Beihu Valley has begun to take shape, and has completed 90% of the progress. A huge and majestic city wall can be seen from a distance, standing high at the narrowest part of the Beihu Valley, which made Zhang Xuan extremely happy. Zhang Xuan did not expect that the pass of the Beihu Valley was progressing so quickly. He didn't even bother to rest. As soon as he arrived at the Guancheng, he climbed to the city to inspect with Su Dingfang and Li Chun.

The construction of the Beihu Valley Pass was originally under the responsibility of Mai Mengcai and the prefect Li Yi. Zhang Xuan made adjustments after Li Chun arrived. Mai Mengcai turned to be responsible for the heightening and widening of the Lulongsai city wall, while the Beihu Valley Pass was under the responsibility of Su Dingfang and Li Chun. The facts proved that this decision was correct. Su Dingfang had strong control over the army and was extremely efficient. Coupled with Li Chun's talented and clever design, the city of this city took only 20 days to take shape, which was a miracle.

Outside the city wall, Su Dingfang pointed to an arch bridge at the bottom and exclaimed sincerely: "Li Shangshu's planning for the bottom of the city gate is like a stroke of a magical stroke. It not only solved the problem of Baoqiu Water's penetration, but also greatly saved the project volume and accelerated the construction speed. He was convinced!"

Zhang Xuan also noticed that at the bottom of the city wall was a crescent-shaped flat arch bridge, only half a person tall, with sharp steel thorns as thick as wrists below. The ice layer had been chiseled open, and the cold and clear river water flowed through the bridge. Zhang Xuan squatted down and looked for a moment, and asked, "Can people get through?"

Li Chun stroked his beard and smiled: "You can dive over to the bottom of the river, but the war horses cannot pass by. If there is no war horse, what combat power does the Turkic army have?"

This creative idea made Zhang Xuan nod and praise, "Li Shangshu said it well. The Turkic army was one, and without war horses, the Turkic soldiers were nothing."

He looked at the towering city wall again and asked with some concern: "Can the arch bridge below bear such a heavy wall above?"

Li Chun hurriedly said: "Your Highness has no idea. Weichen has made full use of the pig iron in the mutual trading warehouse and used pig iron to make an iron frame inside the city wall. There are eight thick iron piles under it. In fact, the iron frame is supporting the wall. Weichen cannot guarantee that it will be safe for ten years, but it can guarantee that it will not collapse within five years. In three years, we can rebuild this city. At that time, Weichen will spend another year to build it carefully, and it will be safe for hundreds of years."

Zhang Xuan smiled, "As long as we can ensure that we don't collapse for a year, our plan will be realized."

At this time, Zhang Xuan suddenly found that this mile-long pass had no city gate. He couldn't help but ask strangely: "Where is the city gate?"

"Your Highness, the city gate is only seven feet wide at the east end. It can just accommodate a carriage to pass, but now it has been sealed with more than one hundred huge rocks. After the war is over, we drag the huge rocks away and the caravan will pass."

Zhang Xuan nodded, and he turned around and climbed to the top of the city five feet high, which was equivalent to the five-story building in later generations. When you climb up and look into the distance, you can see more than ten miles away, and your vision suddenly became wider.

Although the Turks had collected more than 10,000 fugitives from the Central Plains a few years ago, some of them were also craftsmen. They brought the Turks the manufacturing methods of siege weapons and made certain developments in bow making technology, with the strong rise of the Northern Sui Dynasty, a large number of outstanding Hebei craftsmen defected to Qingzhou rather than the Turks. The technological progress of the Turks was still limited, and the five-meter-high city wall made it difficult for the Turks army to attack.

"Your Highness will give this city a name!"

Li Chun smiled and said, "The city gate is almost completed, but it does not have a name yet, and it is not easy for the imperial court to register."

Zhang Xuan thought for a while and said, "Since this business road is called the Beihu Valley, then it is called the Hugu Pass!"

Li Chun and Su Dingfang praised each other again and said with a smile: "I will arrange for someone to prepare the name of the Guan tomorrow, and I also beg your highness to give you a painting of ink."

Although Zhang Xuan's calligraphy is average, it can barely be seen. The more important thing is that if Guan Ming doesn't write an inscription, who dares to interfere? Zhang Xuan nodded and agreed to Li Chun's request.

At this time, Zhang Xuan suddenly saw a low wall a mile away, which surprised him a little. At that time, he was worried that the city gate would not have time to complete the construction when the Turkic army arrived, so he decided to build a low wall with mud bags first. However, now the city gate has been completed with nine floors, and the low wall actually has not made much sense, but it has been built.

"When will that short wall be built?" Zhang Xuan asked, pointing to the short wall in the distance.

Li Chun hurriedly said, "Report to Your Highness, the low wall was completed three days ago. It took us less than five days. The number of people participating in the construction was only a thousand, which did not affect the construction of Hugu Pass."

"Did you use mud bags?"

Li Chun shook his head, "It's not about mud bags, we built the outer frame with giant wood and pig iron, and laid a layer of thick boards inside, filled with gravel on the riverbed, and wooden boards and fences on it to facilitate soldiers' defense above. Although it cannot be compared with the Guancheng built with huge stones, it is as strong and durable as the Guancheng built with huge stones, and is not so easy to destroy. Even if the Turkic army seized it, it has no effect on them, but it is for us to prevent the Turkic army from launching a sneak attack on Hugu Pass."

"The last sentence reached the key point!"

Zhang Xuan said happily: "Whether it is building that low wall or we build beacon towers, it is to prevent sneak attacks from the Turkic army. This is a tactic that the Turkic army has always been good at. I believe they will use it on us, so we must consider various details so that we can calmly face the sneak attacks and long-distance raids of the Turkic army."

Su Dingfang next to him thought something and whispered: "Report to the Grand Commander, I heard that General Pei sent a lot of cavalry scouts to the grassland. Although there is still snow on the grassland, it is possible to march. Can we also send scouts to the grassland? Once the Turks have any trouble, our scouts will immediately send news?"

Zhang Xuan pondered for a moment and said, "It was my order from Yuanqing to send scouts to the grassland, but they were just going to Fuqibo and Dingxiang County. The eastern grassland was Tiel's territory. Once the Turkic army attacked, someone would notify us in time, so there was no need to send scouts to the north. Moreover, once they encountered wolves, the scouts would suffer great losses. We don't need to take this risk. Just build the beacon tower and you will have eyes two hundred miles away."

"I understand!"

Zhang Xuan said in a deep voice: "The most urgent task now is to train the army. At most twenty days, the grassland will be full of spring. At that time, the storm of war will come, so hurry up and hurry up!"

Su Dingfang nodded silently, and Zhang Xuan immediately said to Li Chun: "Although Lu Longsai is easy to defend and difficult to attack, it also needs to strengthen the construction of fortifications. Please ask Li Shangshu to go to Lu Longsai again to see if there are any defense loopholes."

"Tomorrow, Weichen will explain the rest and go to Lu Longsai immediately."

Zhang Xuan nodded, he slowly walked to the city wall and stared at the north from afar. Now the snow on the grassland began to melt, and the Turkic troops should have begun.

As February begins, the warm breath also spreads to the grassland. Although the glacier has not yet thawed, the white snow has begun to melt. The thick snow, which is originally waist-deep, only covers the insteps, and war horses can already gallop on the grassland.

At the intersection of the lower reaches of the Egen River and the Soling River, there is also an endless and abundant grassland, but the Turks gave it to the Sijie tribe of the Tieler Nine Tribes.

On the one hand, this place has always been the homeland of the Sijie tribe. If it is forcibly taken away, it will trigger strong resistance from the Tiel tribes. On the other hand, the Sijie tribe is also the most pro-Turkish tribe among the Tiel tribes. The Turks made a favor and allowed the Sijie tribe to continue to grazing here. However, the Khan of Qimin forced his daughter to Danting, the chief of Sijie, as his wife. Danting's original wife died of illness shortly after it was abolished, which also triggered a fight within Sijie.

That morning, a Turkic cavalry composed of more than 100 people appeared near the tent of Chief Sijie. The galloping horses stirred up mud on the snow. The warriors who were guarding the Chief had discovered that they immediately gathered from all directions and blocked the Turkic cavalry's way.

The head Turkic centurion raised a golden wolf-headed arrow high and shouted sternly: "Khan wolf-headed order, I want to see the Chief Danting immediately."

The Golden Wolf-Head Order is the highest military order of the Turkic Khan. It is usually issued by the Turkic Khan himself, and is only targeted at the chiefs of each tribe. When the Sijie warrior saw the Golden Wolf-Head Order, he did not dare to neglect, so he led the Turkic cavalry to the front of the chief's tent. At this time, the Great Chief Sijie Danting had already walked out of the tent and followed his sons.

Sijie Danting was about fifty years old, which was considered a long life on the grassland, where his average life span was less than 30 years old. His eldest and second sons had died of illness last year and the previous year, and his three daughters had also passed away. Only this chief still lived in high spirits.

Sijie Danting is not tall, but she is very strong. She has an extra-large nose and looks like a purple eggplant growing directly on her face, which is unforgettable.

"What's the matter?"

The Turkic centurion quickly walked forward and raised the Golden Wolf Head Order, "Transfer the Khan's order, Sijie's army gathered immediately and went to the Wangting to wait for the dispatch!"
Chapter completed!