In the face of the numerical superiority of the Sui State, Su Gaiwen's soldiers and horses could only choose to use guerrilla methods to avoid clashes with the main forces of the enemy, and they were well aware of their superiority.

The Sui soldiers suffered a lot in the three campaigns because of the convenience of grain and grass, and even if they landed in the Goryeo, they were not afraid, because they knew that the transportation of troops from the sea was very limited, and the grain and grass needed to be transported for a long time.

However, according to their observations, the Sui soldiers and horses did not have a lot of food and grass, so Su Gavin adopted this tactic of luring the enemy into an ambush circle, and then carried out a superior attack, using bricks and stones, bows and arrows, crossbow arrows.

Originally, this tactic was nothing for hundreds of thousands of soldiers and horses, but the actual situation was very different, and the method adopted by the Koreans did very little damage in the morning, but it could not withstand harassment every day.

Those who came and went, dozens of people were injured today, and dozens of people were injured tomorrow, but bringing these wounded people can slow down the journey of the soldiers and horses of the Sui State, and if you give up, it is equivalent to letting these people die directly.

It was not long before the dilemma, and after the battle, although the soldiers and horses of the Sui State broke through the defense line and finally retreated without supplies, the Goryeo soldiers who also blocked the soldiers and horses of the Sui State were also huge.

Su Gavin thought that it was very necessary for people to intercept them on the frontal battlefield, even if it was sacrifice, otherwise he thought that the speed of the Sui army's attack might fight to hit their city, so that the supply of food would support them to continue the battle.

Although the losses were huge in the end, the last line of defense was also held.

After the Sui soldiers retreated by boat, Su Gavin immediately returned to the city wall on the mountain with his people, and it didn't take long to find that the vanguard had moved.

Su Gavin felt bad all the time, at least 100,000 of the vanguard soldiers who had been observed by the spies had left, and the spies wanted to get close only to be discovered, and fled all the way back, and when they came back, they were already dying.

And the final intelligence is not of much value.

Su Gavin could only think about it, now that there is a city wall as a barrier, even if a million soldiers and horses come, he is very relieved, but he doesn't know what the vanguard is going to do with so many soldiers and horses.

Li De personally led people to fight for the north, and there were no people in the vast land in the process of traveling, and the forests were patchy, and the resources of Wuhua Tianbao were abundant.

Li De is running for resources.

The rush was boring, their speed was fast, and the rest of the time except for rest was spent on the road, and the legs of the vanguard were like eyes, and every direction was clear.

After formulating the plan, the scouts of the vanguard had already set out to explore the way, and drew a map of the places they passed through, and the ranging was measured using the rangefinder researched by Li De's craftsmen.

It was the rangefinder with this one-wheeled wheel in the back of the carriage that calculated the distance by the number of wheels, and their task was to map, mark and draw a map.

The process was long and not done by one person, but by a whole team, and the scouts were just responsible for the wayfinding, as well as the accompanying escorts and surveyors.

With the map in hand, it will naturally be much easier to hurry, and the vanguard has also made signposts on the way, all for future consideration, and it is easy to get lost near the mountain.

The scouts had already set up a gathering place, a small and very hidden place, and after the vanguard arrived at the first front station, after a day's rest, 150,000 people began to get busy.

The supplies they carried were also put to use, and within a few days, a simple barracks was built, without any masonry and wooden walls, and observation posts were set up on the periphery, and the area around the outpost was divided.

The soldiers rested in the usual tents, a tent could accommodate a dozen people, and for a few days what was originally used as an outpost for scouts to observe, now became the base camp of the vanguards.

"How far is it from the Northern Barbarian Tribe?" Li De asked.

The scout in charge of the observation had already investigated the situation clearly, and immediately replied, "Twenty miles away from here, there are several united tribes, the number of which can be more than 30,000, and the number of cattle, sheep and horses is 100,000, but it is not the Northern Barbarian, but a branch of the Tiele tribe, and the specific situation cannot be verified. ”

The scouts are telling the truth, they don't know the situation between the tribes very well, and they only know some of the tribes, such as the Turks and the Northern Barbarians, and they can judge by their appearance, clothing, and language.

However, there are many tribes with different customs and habits, and the scouts can tell that it is one of the Tielers, which is already extraordinary.

"He Bida, send our scouts to investigate the situation, so that Shi Huaiyi and Luo Song are ready to go out at any time, remember that the vanguard should not be too close, and wait for the news of the scouts." Li Dedao.

"Yes." Hobida agreed.

The commanders all had a clear division of labor, and Li De was waiting for the return of the other scouts in the barracks, and it was impossible to conduct a complete search in the northern part of Liaobei.

You can't disperse all 150,000 people, it's easy to startle the snakes, so that the tribes here will know the situation and they will quickly assemble, even if they don't want to fight a tough battle.

Li De still felt that it was the safest to break through one by one quietly, which could minimize the loss.

Moreover, not all peace is resolved through war, and many tribesmen are the same as the Sui people, and they want a peaceful and safe life.

It's just that the living environment makes it impossible for them to achieve it, but it doesn't matter.

"Grand Duke, discover the new tribal station, just to the northeast, at least 20,000 men, dressed in ......," the scout recounted in disbelief.

Not long after Shi Huaiyi, Luo Song and others dispatched, they borrowed and sent back the news of the scouts, and they also found a tribe thirty miles away.

Li De marked all the locations they provided, and immediately sent someone to chase Shi Huaiyi and the others back after reading the situation.

"Grand Duke, has there been a change in plans?" As soon as he entered the tent, he asked.

"Oh, you're here just in time, take a look at the information collected through the back door, the map is marked with the tribes that have been discovered." Li Dedao.

He Bida was very surprised when he looked at it, if several places on the map were tribes, needless to say, they should be a gathering place for a large tribal united ethnic group.

If you attack rashly, then the number of the two sides may not be superior.

The Turks were able to unify many tribes by means of either combining resources, such as cattle, sheep, horses, and populations, or simply suppressing them by force.

This method is not easy for anyone to use, for example, although the vanguard is strong, one of the shortcomings is that they do not know the situation of these tribes.

"What happened to the Grand Governor, why is he in such a hurry to summon us back?" Shi Huaiyi hurriedly asked.

They had just dispatched the cavalry, and they thought something was wrong when they recalled them in such a hurry.