At this moment, the leader of the Khitan tribe, Abao Grotto, was confidently leading a large number of Khitan cavalry to advance in the direction of Black Rock City.

He is a middle-aged man in his forties, known for his bravery, and the Khitan Ten Divisions. At the same time, he is also the leader of the most powerful Wusu tribe in the Khitan tribe. Therefore, he was recommended as the leader of the Khitan tribe by various ministries. It's just that his leader is only in name, and the Khitan tribes are still under the command of their own leaders. Apo Grotto is more like the leader of an alliance.

Originally, they had been sandwiched between the two powerful enemies of Turkic and Goryeo for a long time, and they lived in a nest and tried to survive in the cracks. But since the Sui Dynasty's massive attack on Goryeo last year, their fortunes have been reversed.

As Goryeo was exhausted by the Sui attack, the oppression of the Khitan and Murwei tribes was greatly reduced. Especially this time the Sui army's attack made the Goryeo army even more defeated, and the situation was critical. In the case of frequent emergencies on the front line, the king of Goryeo, Gao Yuan, had to lower his posture and sent a letter to Abao Cave as an equal, saying that the Sui army had invaded Liaodong on a large scale, and Goryeo was in danger. It is hoped that the two sides can reach an alliance and unanimously fight against the Sui army.

After receiving the secret letter, Abao Cave knew that the matter was very important, so he convened a meeting of the leaders of the Khitan tribes to discuss. At the meeting, the opinions of the various ministries were not unanimous.

Some leaders believed that the Sui Dynasty was far stronger than Goryeo, and if they went to rescue Goryeo, they were afraid that the Sui army would attack. Moreover, Goryeo was not very friendly to the Khitan in the first place, and the Khitan did not need to wade into this troubled water.

Some leaders believe that although Goryeo has oppressed the Khitan fiercely before, after all, they are dependent on each other, and once the Turkic or Murwei tribes come to attack, the two sides can often work together to resist the enemy. If Goryeo is allowed to perish. In the event that the Sui army or the Turks attack the Khitan, I am afraid that they will have to wait for death.

When the two sides argued, giving Abao Cave a headache, the Goryeo envoy Fang took out a second secret letter.

In this secret letter, Gao Yuan promised that if the Khitan could send troops to help Goryeo defeat the Sui army, after the war was over, he would cede the 800 miles of abundant water and grass near Changbai Mountain to the Khitan.

As a result, the leaders of the Khitan tribes were all moved, and those who were originally in favor of sending troops strengthened their beliefs, while those who were originally not in favor of wading into this troubled water also wavered in their will.

So, under the temptation of this heavy profit, Abao Cave agreed to send troops to rescue Goryeo.

After sending off the Goryeo envoys, the Khitan Ten Divisions discussed a plan for sending troops: each department sent 3,000 men and horses to form 30,000 cavalry, which was commanded by Abao Cave. Kill the Sui army outside Blackstone City.

Gao Yuan's request was very simple, that is, to hold back the Northern Route Army of the Sui army, so that it could no longer attack forward, especially not to allow it to conquer Black Rock City. Because that would cut off Goryeo's escape route to the Khitan and Murowei. Of course, this plan is not to be told to the Khitans.

Apo Cave was very satisfied with Goryeo's request. After all, he just wanted him to drag the Sui army, instead of fighting hard with the Sui army, and he was still very satisfied with this task.

He also believed that on this Liaodong Plain, with his Khitan light cavalry coming and going like the wind, he could definitely entangle the Northern Route Army of the Sui Army to death. Make it impossible for it to let go of the attack on Blackstone City.

"Big brother, are we in too haste to send troops this time? I heard that the Sui Dynasty was a stronger country than the Turks, and the army was more than the whole of Goryeo, otherwise it would not have been defeated by Goryeo. It would be unwise for us to provoke such an enemy! His sworn brother, the leader of the other Khitan tribe, Zamuhe, was worried.

"Afraid of what? Our Khitan iron rider rides up and down the steppe like the wind, and if we meet the Turks, we may be able to be afraid. Although the Sui army is powerful, most of them are infantry, can't we still run if we can't beat it? As long as you hold back the Sui army and don't let them take Black Rock City, you can give an account to Gao Yuan's guy! Abao Grotto was unimpressed.

Zamu thought about it too, so he put his heart at ease. The mighty queue of the Khitan army overshadowed the sunshine in spring.

"Ahead is Dongping Valley! After that valley pass, we were not far from Blackstone City. Keep up the good work, everyone! When the Sui people were having dinner, kill them by surprise! Abao said excitedly as he saw the mouth of the valley appearing on the horizon ahead.

After the Khitans received the order, they hurried up their horses and tried to rush through the valley in one fell swoop. However, as they got closer and closer to the valley mouth, they were surprised to find that a fence and arrow tower had been erected in the originally flat and spacious valley mouth. Someone set up camp here and blocked the way.

"Hey, someone got the first step?" Zamuhe was stunned for a moment, but he reacted immediately. There could be no Goryeo army here, it could only be the Sui army.

Seeing this, Abao Cave and Zamuhe glanced at each other, and they couldn't help but look at each other. To get to Black Rock City, this Dongping Valley was a must-go, otherwise they would have to make a detour of hundreds of miles, from the other side of the mountain.

Although they could also climb over the mountains, they would not be able to carry their horses with them. After that, he became an infantryman. And the infantry of the Sui army was strong, and the Khitans had heard of it for a long time. Let them use infantry to attack the main force of the Sui army, and they don't dare to borrow the courage of the three of them.

"Big brother, what should I do? It seems that the Sui army has been prepared for a long time! Zamuhe said cautiously, "Otherwise, let's go back." It's not okay to fight hard with the Sui army! ”

Abao Grottoes was able to become the leader of the Khitans, and naturally he was not an ordinary person. After thinking for a moment, he shook his head and said, "There won't be many people in the Sui army, and I heard the Goryeo envoy say that the army they attacked Black Rock City was only fifty or sixty thousand people, how many troops can they allocate here to guard against us?" I don't think it's five or six thousand at most. Besides, there are still fresh branches on their fence, which are obviously trees that have just been cut down, and it is estimated that they should have been erected in the past two days. Can such a hastily built camp stop our Khitan iron cavalry? ”

After a pause, he said again: "This time, the people of the clan are waiting for the news of our triumph. But when we went back, we just told them: because we saw that the Sui army had built a camp at the mouth of Dongping Valley, so we went home, so what would they think of us? And there is no way to explain it to Goryeo! ”

Zamu thought the same, and Fang nodded. But then he wondered, "What about now?" Shall we start attacking? ”

"Hmmm! You first lead 5,000 men and horses to attack, see how many troops the Sui army has, and see how strong their combat effectiveness is! Abao said.

At this time, at the mouth of the Dongping Valley, there was a camp that had just been erected. It happened to be in the way of the Abao Grottoes going south to Black Rock City.

This is the camp set up by Yu Wenming, and the location chosen to camp is also specially studied by Wei Chi Jingde. At present, he has arranged many fortifications in front of the gate of the camp, although because of the hasty construction, it is far less stable than the Sui army camp on the north road outside the Black Rock City, but it can also effectively prevent the enemy from rushing the camp.

However, to the surprise of Abao Grottoes, the Sui army in front did not intend to blindly defend it, but sent 2,000 infantry out of the camp to fight against Abao Grottoes. However, they did not go far from the camp and stood in front of the camp gate.

"Sons! Offensive! Let the Sui people taste the power of our Khitan iron horse! Zamuhe roared, and the five thousand cavalry behind him began to move forward slowly, leaving the Khitan brigade.

After marching two miles, Zamuhe ordered to start accelerating, and the five thousand Khitan cavalrymen grabbed the reins one by one, lay down on their horses, swung their whips and slammed their horses' buttocks, and entered the sprint stage.

Just as Zamuhe began to give the order to attack, the Sui army at the mouth of Dongping Valley also quickly received information from the scouts that the Khitan brigade had appeared.

However, Yu Wenming had already arranged for this, and Wei Chi Jingde immediately led two thousand infantry along the fence in front of the camp gate, with their backs to the large camp and set up a position.

"Attention the whole army! The Khitans are about to be killed! The location is due north! The whole army is in defensive positions and ready to meet the enemy! Wei Chi Jingde ordered.

The 2,000 infantry under his command immediately set up a defensive position, and at the fore was a spear and shield formation composed of shield men and pikemen, mainly to resist the onslaught of the enemy cavalry, and behind them were the archers, who mainly shot the enemy in large numbers when the enemy cavalry charged, and after the real hand-to-hand combat, they did not have much effect.

The Sui army waited for a pillar of incense in a tense defensive state, but finally heard a rumbling sound of people shouting horses and neighing from due north.

At the same time, all the Sui soldiers felt the ground trembling slightly, and the experienced veterans immediately judged that this was the shaking of horses' hooves brought by the rush of a large number of cavalry.

Wei Chi Jingde looked due north, only to see a black line appear on the horizon in the distance, this black line slowly became thicker and larger, and gradually rushed towards the phalanx of the Sui army.

"The Khitans have been killed!" After Wei Chi Jingde saw the Khitan cavalry appear, he breathed a sigh of relief, and he kept lining up the formation in this way, and waited nervously with all his attention.

And for heavily armored infantry, standing for such a long time is a high test of will and physical strength. Although his soldiers were elite soldiers, they were also a little tired.

"Brothers, keep going!" Wei Chi Jingde secretly said that it was not good in his heart, so he hurriedly cheered up his soldiers.

However, he also knew that this was a helpless thing, and anyone who had just experienced a battle, and then marched for many days in a row, would be tired. But now is clearly not a good time to think about it. He immediately gave the order, and his infantry immediately went into a state of meeting the enemy.

At this time, Zamuhe raised the spear in his hand and shouted, "Kill! Kill all these Sui people! Victory belongs to our invincible Khitan warriors! ”

The five thousand Khitan cavalry behind him were all very poorly equipped, all of them were wearing animal skins, their faces were dark, and the top of their heads was also shaved bald, looking fierce.

They rode on tall horses, and they all raised their weapons in response and screamed.

When the morale was up, Zamu Hefang pointed his spear forward and shouted, "Charge!" ”

With that, he took the lead in swinging his spear and slapping his horse forward.

More than 5,000 Khitan cavalry followed behind him, and rushed towards the Sui army that was waiting in front of him with great momentum......