"Your Majesty, isn't this a little smaller than Han and Tang?" Yao Changsheng raised his sword eyebrows and said, looking at Chu Jiu with a light brow.

When Chu Jiu shook his head and laughed, "What's the matter? You really think that the land where the sun and the moon shine are all Han territory! Changsheng's ambition is quite big."

"If you can't reach the sun and the moon, you can get bows and arrows. Now it should be said that the cannons are all within the range of Han territory." Yao Changsheng said arrogantly with his eyebrows raised.

"Haha..." Chu Jiu smiled and said, "First think about how the Western Regions can walk through the Gobi Desert safely! I am not familiar with these soldiers, and water sources are a big problem."

"Yeah!" Yao Changsheng pondered for a moment after hearing this, suddenly said in front of him, "Your Majesty, the collection of books in this palace should have records. How the journey of Dayan to the west back then was very valuable and could help us avoid detours."

Chu Jiu pointed his index finger at him and said, "You are right, I will come and look for someone immediately." Suddenly, he remembered, "Those books should be Mongolian text!"

"The emperor is looking for the old Hanlins of the previous dynasty. I think they should be very willing. They should know more than one language." Yao Changsheng reminded him after hearing this, "There are also tribes in the southwest, and tribes of all sizes are also in a mess."

"Yeah!" Chu Jiu nodded and said, "I will enable it as appropriate."

"I'm a little surprised that the Hetao area is well protected." Chu Jiu said to him with a puzzled face.

"Because the Hetao area is a strategic location and a springboard for grassland wolf to attack the heartland of the Central Plains, others are not allowed to be involved. If no one moves, they will naturally not be destroyed." Yao Changsheng looked at him with a slightly cold look in his eyes and said.

"Don't the big swallow raise horses?" Chu Jiu said to him with a puzzled look on his face.

"Raising horses also requires money. Emperor Yan himself has lived a clean and honest life, so where can he get the money? Even if he has money, he is not enough to be greedy." Yao Changsheng rolled his eyes and said, "What other horses can he raise!"

"No wonder our cavalry is also rare. I was afraid of the Iron Cavalry of the Great Yan before." Chu Jiu said with emotion. When he talked about Emperor Yan, he remembered Emperor Yan's private warehouse and told Yao Changsheng in detail.

Yao Changsheng was dumbfounded and didn't know what words to express.

"Dad!" Chu Zeyuan and the others stood outside the hall and shouted.

"Come in quickly." Chu Jiu's eyes lit up when he heard this and shouted loudly, looking at the door of the hall.

The three brothers Chu Zeyuan walked in, Yao Changsheng stood up and held his fists with his hands and bowed, "Your Highness, the Second Highness, and the Third Highness."

"Uncle Yao." Chu Zeyuan and the other two bowed to Yao Changsheng.

Yao Changsheng avoided it. This courtesy made Chu Jiu shook his black eyes lightly, and he shook his head slightly in his heart, making him not know what to say.

"Sit down and talk." Chu Jiu looked at them and said, "Are you hungry? Let's send some snacks first."

"I'm really hungry." Chu Ershen touched his stomach and said with a smile.

The servants beside Chu Jiuchuan went to the imperial kitchen to bring some refreshments.

"The snacks made from cow milk are quite delicious." Chu Jiu said with his bright eyes at Yao Changsheng, and his eyes fell on Chu Zeyuan who had already sat down and said, "Why are you here? You are not studying in the study room."

Yao Changsheng saw the three brothers sitting on the drum stool, and then he lifted his robe and sat down.

"We heard that Uncle Yao is here, so hehe..." Mr. Chu looked at Chu Jiu flatteringly, quickly changed the subject and said, "Dad, what are you and Uncle Yao talking about?"

Chu Jiu didn’t know these two little tricks, “We are talking about the Hetao area.”

Chu Zeyuan got up and walked to the wall, and opened the map.

"This is a bit rough." Chu Zeyuan smiled.

"I can make them more refined when I come back this time." Yao Changsheng looked at the huge map in front of him with warm eyes.

"I know this Hetao area." Chu Er Shao looked at them with a red face and said, "The Hetao area is the border between the Central Plains dynasty and the northern grassland wolf."

Chu Zeyuan's ears moved slightly and said, "You can wait a moment before talking, let's finish the snack."

As soon as he finished speaking, the attendant was carrying a food box outside.

Chu Jiu asked them to come in and set the refreshments. After the attendant stepped down, he said, "This snack made with milk is soft and delicious, and the children love it."

"This is what the master has done." Chu Zeyuan pushed the plate at Yao Changsheng and said.

"My wife is tireless in eating." Yao Changsheng's eyes showed intoxicating sweetness.

"Some of it is too much sugar-free, and ordinary people can't afford it." Chu Jiu looked at him with some regret and said.

"Sugar?" Yao Changsheng raised his sword eyebrows and said, looking at him.

"What's the idea of ​​Changsheng?" Chu Jiu looked at him curiously and said.

"My wife once said that sugar will turn as white as salt." Yao Changsheng thought for a while and looked at them and said.

"Can you increase the output?" Chu Jiu said with a bright look at him.

"I have to go back and ask about this." Yao Changsheng said with conservative look at him.

"Using the character of the master, you can do it." Chu Ershao said confidently, "The master is very stubborn about increasing the yield."

"Haha..." Yao Changsheng shook his head and laughed when he heard this. He was really right about this.

"I know that most of the sugar is made of sugar cane, and there are many sugar cane in the south. Why haven't I heard my brother and sister mentioned it for so many years?" Chu Jiuhei looked at him with his black eyes and suddenly remembered.

"My wife mentioned it early, probably when His Majesty first took down Jinling." Yao Changsheng thought carefully and said, "I mentioned it casually at that time, and the other places have not been taken down yet. This money cannot be earned by others."

"Hehe... it's the tone of my brother and sister-in-law's speech." Chu Jiu smiled when he heard this.

"My wife doesn't like to eat candy, and most of the milk is herding cattle and sheep in the north. This matter was put aside." Yao Changsheng looked at him with gentle eyes and explained.

"It's not too late now." Chu Jiu said with a smile, a light of inspiration flashed in his mind, but it was interrupted by his son.

"Uncle Yao, eat quickly." Chu Zeyuan introduced enthusiastically.

"Okay!" Yao Changsheng nodded with a smile.

Yao Changsheng and his friends ate all the snacks and biscuits on the round table.

"Now I can say it!" Chu Ershao clapped his hands and said.

"Okay! Let's see what our second primary school can say?" Chu Jiu leaned back on the back of the chair and said with his eyes looking straight at him.

Chu Ershao walked to the map and pointed at the map, "In history, this grassland wolf mainly raided the Central Plains through: Hexi Corridor, Hetao Region, and the Sixteen Prefectures of Yanyun. From the Qin Dynasty to the Song Dynasty, the Central Plains Dynasty established its capital in Chang'an, Luoyang, Tokyo Bianliang and other places. The key defenses are in the Hexi Corridor and the Hetao Plain. The Hexi Corridor is very close to Guanzhong, and the terrain is flat, which facilitates cavalry raids."

"Yeah!" Chu Jiu looked at him with a smile and nodded, looking at the Jiuqu Yellow River, "The Yellow River is full of harm and profit!"

"The Yangtze River is on the south of the Yangtze River." Chu Zeyuan said after hearing this.

Second Young Master Chu pointed to the map and continued, "After the Jin Dynasty crossed south, the south was considered to have risen. The areas of Datong and Shuozhou in Shanxi were called Yunzhou in ancient times. The four Hexi counties set up in the Western Han Dynasty were like four buffer zones, which could delay the raid of cavalry. The four Hexi counties: Wuwei County, Zhangye County, Jiuquan County, and Dunhuang County. Once the Hetao Plain is captured, the cavalry of the grassland wolf can easily reach the core of the Central Plains. The Hetao Plain is more a defensive front line of the Central Plains, or as a springboard for attack by the enemy."

"But let the flying general of Longcheng be there, and the Hu horses will not be able to cross the Yin Mountains." Chu Jiu looked at him with relief and said, "Now I have a deeper understanding of this poem." He took a deep breath and said, "Yanyun saved his life, Hetao was strengthened, Hexi advanced, Chang'an stabilized the capital, Hetao was the focus of defense, Yanjing established the capital, and Yanyun's sixteen prefectures were the focus. In terms of grassland wolf, from the Huns to the Turks, and then to the previous dynasty, there was a clear trend of migration eastward."

"Yeah!" Yao Changsheng nodded in agreement, "The Hetao Plain is still an important horse-raising land. Losing Hetao will lead to a significant increase in the cost of war horses. Determined to Yanjing, and the focus of defense will be changed to the Sixteen Prefectures of Yanyun."

Chu Jiu looked at his son and said seriously, "You guys, I set up the capital of Yanjing for precautions, to beat people at any time, rather than letting you stick out your neck and letting you kill me."

Yao Changsheng was stunned when he heard this, smiling without saying a word. The world was to be handed over to them.

"Dad! We don't know how to do it!" Chu Zeyuan said sternly with a stern face.

"I believe you won't, but you won't know if you have your descendants. It's hard to say whether you will be as good as Emperor Yan in a wealthy nest." Chu Jiu looked at them with dark eyes.

"Dad, we have a lesson in the past, we..." Mr. Chu argued urgently.

"Second boy, there are so many lessons from this. Look at how many people have learned from it." Chu Jiu said with his index finger on the imperial case.

Chu Er Shao's little mouth was opened and closed, but he couldn't speak. There were too many in history books and he couldn't count them.

"Okay, this question! Let's discuss it slowly, and now we will continue to the Hetao area." Chu Jiu looked at them with affectionate eyes and said, "Defending the enemy outside the national gate, this capital is not a national gate, but an existence like Chang'an and Luoyang, not far or near to the strategic direction, and not to ignore the beginning and end."

"Yeah!" Chu Ershao and his mentor nodded and said, "Hetao area is divided into three major parts: front, back, and Western Taurus Plain. Historically, the Western Taurus military defense was very important, and many commanders were set up on both sides of the Yellow River, with county seats! Four Hetao counties: Shuofang County, Wuyuan County, Yunzhong County, and Dingxiang County."
Chapter completed!