After the end of the alliance in Zhangjiakou, Zhu Youzhen planned to go north to Chengde again and regain control of the situation in western Liaoning. However, Lin Dan Khan met with him again before leaving, and offered to send a force north with him.

Zhu Youzhen learned about it, and it turned out that Lin Dan Khan did not know about the war between the Later Jin and the Ming Dynasty at this time, but followed the advice of Gunchuk Taiji and became interested in recovering Chahanhot. As a city he personally selected to build, Chahanhot was originally the capital of the Mongol Empire.

Under pressure from the Later Jin, he had to abandon his homeland in Liaodong and ordered the Chahar tribes to move westward, trying to reunite the left and right wings of the Mongols under his own court. In order to realize this dream of the unity of the Mongolian tribes, he even gave up the Chahanhot built by his own hands.

However, when he formed an alliance with Chongzhen, the worry that the various departments were too far away from him and out of control was not so strong, and with the materials of the Ming Dynasty, it became possible to hold Chahanhot. Therefore, he became interested in recovering Chahanhot, and using this as his heart to subdue the nearby tribes, blocking the road of Houjin's westward expedition.

Although he still had a lot of wariness about Da Ming, no matter how he calculated, he found that this plan was not harmful to him. After the reconquest of Chahanhot, the Monan grassland from the west of the Great Khing'an Mountains to the Hetao region became a safe hinterland for the Chahar region, and it was not trapped near the Tumut River as it is now.

Having a place for the Chahar tribe to recuperate is also the most urgent need of the Chahar tribe at present before the unification of the Mongol tribes. After thinking about it repeatedly, Lin Dan Khan couldn't help but want to give it a try, but before that, he still wanted to see how much power the Ming Kingdom had in the grassland, so as to determine how much he supported this plan.

Regarding Lin Danhan's suggestion, Zhu Youzhen only thought for a moment and agreed. And after hearing about it, the newly baked Chotu Khan also approached Chongzhen and expressed his desire to let his son serve the emperor.

So when Chongzhen returned to Chengde, in addition to the six battalions of cavalry of his own guards, the six battalions of Fengzhen cavalry led by Cao Bianjiao, the 800 Chahar cavalry led by Gui Yingcha and the 300 Mobei cavalry led by Arslan. With the addition of a heavy army, this team reached 5,000 people, and Chongzhen was much more spectacular when he came to Zhangjiakou.

Because he was worried about the war in western Liaoning and the grassland, Chongzhen only took 10 days to arrive in Chengde, and the letter sent by Sun Chengzong from Ningyuan also happened to arrive in Chengde at this time and was handed over to Chongzhen.

Regarding Sun Chengzong's letter, Zhu Youzhen only took one night to make a decision. He signed Sun Chengzong's proclamation on the establishment of a wartime base camp, officially granting Sun Chengzong the command power of the front.

At the same time, Chongzhen also wrote a reply letter to Sun Chengzong, agreeing with Sun Chengzong's decision on the battle plan, but he rejected the other party's proposal, handed over the command of the armies outside Jizhou Pass to Wu Huai and Zhou Wei, and returned to Zunhua or Yongping to sit in town.

On December 8, after resting for a day in Chengde, the emperor set out for the source of the Daling River to the north. At this time, it was almost 15 days before Mangui was surrounded by Songshan; It was exactly 13 days before Du Du broke through the big tent of Karaqin Subudi.

Six days later, Chongzhen and Wu Huai's road army met at Tazigou at the source of the Daling River, and at this time, the news that Du Du had broken through the Karaqin Subu region and captured thousands of people and more than 100,000 livestock reached Chongzhen's ears. The harvest of the first army of the basic Dudu has exceeded the sum of the trophies of the Western Route Army and the Route Army.

The captive tribes and livestock were placed between Qingcheng and Tazigou, and the Mongol tribes who grazed from Chengde to the area beyond the Yizhou Guanqiang basically all submitted to the Ming Dynasty. Some tribes who were unwilling to submit to the Ming either retreated to the north of Chahanhot or hid in the Yiju region.

When Chongzhen arrived at Tazigou, the mountains and grasslands in this area were already covered with snow, and the thickness of the snow layer on the ground had reached the instep. Fortunately, the sky is starting to clear up, and there is no sign of continued blizzards for the time being. This layer of snow on the ground has become the best sledding field.

After hearing about Du Du's achievements, Zhu Youzhen praised the martial arts of the Eight Banners of Loyalty and Righteousness in front of the generals, and sent envoys to commend Du Du and other generals of the Eastern Route Army. He then gathered the generals of the Route Army and began to discuss how to deal with the Houjin invasion.

The information from Ning Yuan's base camp was known to everyone by Wednesday's fearful recitation. Previously, everyone knew that the situation in western Liaoning was not very good, but they didn't expect Mangui to be surrounded.

Then Wednesday said the two countermeasures proposed by the base camp, allowing everyone to freely express their opinions on these two countermeasures. Most of the generals, including Wu Huai, chose Li Hongyuan's battle plan, believing that although this plan was a bit risky, it was the one with the least investment and the greatest chance of success.

200 miles from Tazigou to Phoenix Mountain, 180 miles from Phoenix Mountain to Yizhou, Phoenix Mountain is the throat of the dam grassland into western Liaoning, and now the Subu land is defeated by Dudu, and Phoenix Mountain is also temporarily in a state of unguarded.

Therefore, when everyone was inclined to Li Hongyuan's battle plan, they thought that they should seize Phoenix Mountain as soon as possible, and then they either advanced or retreated.

This military meeting quickly reached a consensus, first, to send a force as soon as possible to seize the Phoenix Mountain road; the second is to order the main force of the East Route Army to move closer to Phoenix Mountain as a reserve force of the Route Army; The third is to order the Western Route Army to come and take over the defense of Tazigou and protect the rear road for the army.

Four days later, Chongzhen's camp moved to Phoenix Mountain, which was previously known as Longshan and Helongshan, and in recent decades, it has been renamed Phoenix Mountain.

In the first year of Jin Yonghe (345 AD), in the summer and April, a black dragon and a white dragon were seen in Longshan, and Murong Hao, the king of Yan, led the officials to watch it, went to the dragon for more than 200 steps, and sacrificed it to the ether prison. The two dragons frolicked and walked away. Afterwards, Murong Hao built a Buddhist temple in the mountain, called Longxiang Buddhist Temple, and built a city under the mountain called Longcheng.

However, when Chongzhen came here, there was no trace of Longcheng under the mountain, and there were only a few remnants of the Longxiang Buddhist Temple in Phoenix Mountain, which was no longer the grand occasion of the first Zen temple in the north. Looking at the broken Buddha statues in the main hall and the collapsed courtyard wall outside the hall, Zhu Youzhen shook his head very much.

Hai Lanzhu, who accompanied the emperor here, was in a good mood, and she persuaded Chongzhen: "Since Your Majesty has come here, why not enter the palace and worship." This temple is called Long Xiang, isn't it Your Majesty's good luck, Your Majesty entered Yiju from this, it is the Dragon Xiang in the sky, a good omen. ”

As a materialist, Zhu Youzhen naturally would not believe in this superstition, but he looked at the expressions of the generals accompanying him and swallowed back the words of rebuttal. Although he didn't believe it, these soldiers were very credible, and Ma was going to fight with Houjin, and he didn't want to touch everyone's brows.

"Also, the dragon soars in the sky, what other problems can trap us. Go, let the people prepare three animals, and I will sacrifice heaven and earth here, and pray for the success of our army's expedition..."

On December 18 of the third year of Chongzhen, Zhu Youzhen led the army to set up a sacrifice in the Longxiang Buddhist Temple of Phoenix Mountain, and the morale of the whole army was great, thinking that the victory of this expedition was inevitable.

On the same day, the Eastern Route Army once again sent an envoy to report to the emperor that six days ago, Du Du once again ventured with more than 500 Zhongyi Eight Banners and more than 400 selected Horqin warriors from Qidaoling, Liulongtai, and Liulonggou all the way into the Yizhou area, saying that he wanted to explore the reality of Yizhou and interfere with the rhythm of the Later Jin army's attack on Jinzhou and Ningyuan.

Although it is difficult to travel all the way to Qidaoling, Liulongtai and Liulonggou, six days is enough for Du Du and others to enter the Yizhou area. In this case, if the road army continues to advance with the whole army, it is possible to crash head-on into the Houjin army that has returned to help, and the quick strategy formulated by everyone before may not be feasible.

In the afternoon of the same day, Zhu Youzhen convened the generals again to discuss, and after discussing for more than an hour, Zhu Youzhen finally made up his mind and said: "Although the move of the Eastern Route Army is a bit reckless, the posture of the commander of the Eastern Route Army in actively seeking battle is still very commendable. Since I had already promised Du Du to act cheaply, it was not a mistake for him to use his subjective initiative to break into Yizhou.

The Eastern Route Army has made outstanding contributions in this expedition, and I must not allow them to lose too much in Yiju, otherwise who else in the army will actively seek war in the future? Therefore, we must first send a cavalry to meet Du Du, and if anything is wrong, we must also let them retreat to Phoenix Mountain.

As a result of Du Du's actions, the suddenness of our army's surprise attack on Uiju has disappeared. Jinzhou to Yizhou is only more than 100 miles, Phoenix Mountain to Yizhou is still close, and the road is flat and the vision is wide, and it is also a matter of 3 or 4 days for Houjin to mobilize people and horses to help. In other words, when we received Dudu, it was almost time for Houjin's army to come back to help.

Under such circumstances, if the main force of our army continues to advance, it is possible that it will be entangled by the Houjin army, and it will become a situation in which the Houjin army is constantly cutting off and pestering. If the situation really becomes so bad, it is unknown how many of our troops can retreat to Phoenix Mountain. In order to unravel the siege of Ningjin, it is not reasonable to trap himself in it.

Except for the Daling River Valley, the other mountain roads are difficult to walk, and it is not suitable for large troops to advance after the snow.

The valley of the Daling River from here to Yiju is extremely narrow, and it is difficult to accommodate a large group of men and horses to fight, but more than 80 miles northeast of Phoenix Mountain, there is a branch river of the Daling River, which is called the Yakniu River. The Daejeong River crosses here and begins to bend eastward, and finally flows southeast into Uiju.

The junction of the Yakniu River and the Daling River is a gentle slope and an open field, which is enough to accommodate the cavalry to fight in formation.

What I mean is that when our army sends troops to meet Du Du, it is better to show the enemy weakness, so that the Houjin army thinks that there are so many men and horses that our army has broken into Yizhou, and then lure the Houjin reinforcements to pursue. And the main force of our army waited for work at the confluence of the Yakniu River and the Daling River, and surrounded and annihilated the Houjin reinforcements who pursued Du Du and others..."