In the first month of the eighth year of the Great Cause, on the eve of the army's imminent departure, the arrogant Yang Guang questioned the famous Heshui Lingyu: "The people of Goryeo are not yet a big county in our country. ”

Yu Zhen replied: "It is Keke, but in the humble opinion of the ministers, it is best for Your Majesty not to go to the levy in person." ”

Yang Guang's face changed: "I am now gathering a large army here, how can I retreat first without seeing the enemy army?" ”

Yu asked: "If you can't win the battle, I'm afraid it will damage Your Majesty's prestige." If His Majesty stays in Jicheng, guides and teaches strategy, and hands over the command to the generals of various armies, let the fierce generals attack quickly, and take them by surprise, they will definitely be able to conquer. Military aircraft lie in speed, and sluggishness will be useless. ”

Yang Guang said unhappily: "Since you are afraid, you can stay here." ”

Geng Xun, the supervisor of the Right Shangfang Agency, wrote to Yang Guang earnestly persuaded him to stay in Jicheng, Yang Guang was furious and ordered Geng Xun to be beheaded left and right.

The Goryeo soldiers on the other side also knew that the war was coming, because King Gao Yuan had just condoled the whole army, and there were long-term preparations to resist the Sui, so the morale of the Goryeo soldiers was very high at this time, and there was not much fear.

The people of Goryeo were not afraid of the million-strong army of the Sui Dynasty, firstly, because Emperor Wen had failed in his expedition to Goryeo, and secondly, when he knew that in the fifth year of the Great Cause, Yang Guang conquered Tuyuhun in the northwest, and Tuyuhun insisted on resisting, and the Sui army suffered heavy casualties.

Goryeo resisted the Sui Dynasty army and used the natural barrier of Liaoshui as the first line of defense, Yalu River (present-day Yalu River) as the second line of defense, and Sasu (present-day Qingchuan River) as the third line of defense.

In the Liaoshui defense line, Liaodong City (now Liaoyang County) is the core.

Liaodong city control Rong raccoon, limited to the island, Han to cut off the left arm of the Xiongnu, Murong and Liaodong City, then encroach on the thistle, the establishment of the Yan State, for the disaster of the Central Plains, Goryeo got this city, year after year after the reinforcement, in fact, it is the first strong city in the northeast, but also "negative mountains face the sea, the water is deep and the soil is extensive, the grass and trees are abundant, and the grain is self-sufficient".

Because of the strategic and geographical importance of Liaodong City, this place was the main battlefield of the battle between Sui and Goryeo.

The most important line of defense against the Sui Dynasty in Goryeo was the Yalu Water of the second line of defense.

It is recorded in the "Hejaz": "There is Ma Zishui in Gaima County, Yuansu County, southwest to Xi'anping County, Liaodong County, into the sea, passing through County 2, traveling 1,100 li, and County 2, that is, Yuansu and Liaodong." ”

In the upper reaches of the Yalu water, there is a mountain covering the horse, which is considered a barrier. (Gaima Mountain, the ancient name is Buxian Mountain, the Han Dynasty is called Shan Dan Daling, also known as Gaima Mountain, the city of Taibai Mountain in the Later Wei Dynasty, and then there are Taishan, Taihuang Mountain and other titles, from the Jin Dynasty to the modern era, called Changbai Mountain.) ）

The center of gravity of Yalu Water's defense is Marudu Castle (now Anxian County, Ji'an City), which is willing to be the former capital of Goryeo, east of the boiling water under Marudu Mountain.

When Goryeo built this Marudu Castle, it was a castle built according to danger, and there were many mountains and deep valleys near the city, and there were remnants of Gaima Mountain as a natural barrier in the north of the city, and in the west of Marudu Castle, there was a new city, the northeast of the new city, and the city arches such as Nansu and Mudi, which jointly built a strong line of resistance.

The last line of defense in Goryeo, the Sasu defense line, is surrounded by a land of Pingchuan, and after passing the Sashui until Pyongyang, there is no danger to defend, so the Sasu defense line is actually the last lifeline of Goryeo.

On the second day of the first month of the eighth year of the Great Cause, Yang Guang sacrificed the land in the south of Sangganshui, worshiped the heavens in the south of Linshuo Palace, and worshiped Matsu (not Mazu/Matsu in the southeast coastal area) in the north of Jicheng City.

On the third day of the first lunar month, Yang Guang issued an edict ordering to immediately set off in order to conquer Goryeo!

Before the Sui army marched from the east of Jicheng, Yang Guang personally wore a military uniform and said to the generals: "Now the conquest of Goryeo, not for fame, the generals may not know my intentions, want to raid lightly, fight alone, set up a name, in order to invite merit, this is not the way of the army, you and so on, will be divided into three roads, there is an attack, you must know each other in three ways, you must not light the army alone, so as to be defeated." ”

Then, Yang Guang glanced at all the generals and continued: "All military advances and stops need to be reported and reported, and you can't act without authorization!" ”

When all the generals heard this, they all looked at each other and thought in their hearts: "If this is the case, then how can this battle be fought?" ”

Geng Xun, the supervisor of the Right Shangfang Agency, who had just been almost killed the day before yesterday, heard about this in prison and cried out loudly.

After that, the armies of all walks of life began to advance with Pyongyang, the capital of Goryeo, as the general goal, and Liaodong City and Yalu Water as the intermediate targets.

When the armies went out, the first regiment of the cavalry of the first army went first, and each team was separated by fifteen paces, and then one army was sent out every day, and the distance between the front and back of each army was only forty miles, and the advance of one battalion after another was completed after forty days.

The armies were connected from head to end, the drums and horns were heard from each other, and the flags were connected for 960 miles. Yang Guang's 12 guards of the imperial camp and the six armies of the front and rear of the inside and outside set off last, and the team stretched for 80 miles.

This kind of teacher situation is unprecedented in ancient and modern times.

Duan Wenzhen, the Marquis of Xianghou in Beiping, was the secretary of the military department, and now he is also the general of Zuohou Wei, leading the army out of Nansu Road.

When Duan Wenzhen led the army to the way, due to overwork and cold, he suddenly became very ill, so he expressed to Yang Guang: "Yidi is cunning, and it must be strictly guarded, and they say that the conditions for surrender should not be accepted in a hurry." The stagnant water has just fallen, so don't delay it. I only hope that Your Majesty will strictly restrain all armies, gallop quickly, advance by land and water, and take it by surprise, then Pyongyang, an isolated city, is bound to be conquered.

If the foundation of Goryeo was overturned, the rest of the castles would naturally collapse themselves. However, if we cannot seize the opportunity immediately, if we encounter continuous autumn rains, we will fall into a difficult and dangerous situation, the army will run out of food, the strong enemy will be in front, and the people will be behind, if we still hesitate, it will not be the best policy. ”

On March 12, Duan Wenzhen died, and the Sui Dynasty army had not yet made official contact with Goryeo, so he folded a general, and as for Duan Wenzhen's recital for Yang Guang before his death, Yang Guang only glanced at it, and then still fell.

If Yang Guang could really do what Duan Wenzhen said, the outcome of this war might not be the same, and then, there would be no ifs.

On March 14, Yang Guang began to command the army, and the Sui army advanced to the shore of Liaoshui. After the armies of all walks of life were assembled, the Liaoshui lined up the formation, and the Goryeo soldiers relied on the Liaoshui to defend it, and the Sui soldiers suffered countless casualties and could not cross the Liaoshui.

When the 38-year-old Zuotunwei general Mai Tiezhu saw this, he said to the people: "The life of the eldest husband has its own destiny, how can he burn the bridge of his nose with moxibustion, spray his nose with guati, cure the fever and not heal, and lie down and die in the arms of his children?" ”

So he asked himself to be the striker, wanting to lead his troops to break through the Liaoshui defense line in Goryeo.