Goguryeo is a separatist regime in ancient China. It existed from the 1st century BC to the 7th century AD. Its territory roughly includes parts of northeast my country and the northern part of the Korean Peninsula. Although its name is very similar to the later Goryeo dynasty, the two have no direct inheritance relationship.
The unified dynasty in my country's history has always been highly vigilant against the separatist regime in the north. If conditions permit, a unified regime will never appear in the north. The same is true for The Sui Dynasty . During the Emperor Wen of Sui, the combination of differentiation and disintegration and force strikes was adopted to eliminate the powerful Turkic and Tuyuhun regimes. The Goguryeo regime during the Sui Dynasty also entered a stage of prosperity, posing a huge threat to the northern part of the Sui Dynasty. Therefore, Emperor Yang of Sui Dynasty did not come to pay tribute and sent troops to attack Goguryeo. However, unexpectedly, the Sui Dynasty dispatched about 2 million troops, but failed to conquer the small Goguryeo.
In 612 AD, in the eighth year of Daye in the Sui Dynasty, Emperor Yang Guang of Sui sent his troops to the East for the first time. Yang Guang is a person who loves great achievements. He always seeks completeness and speed in his work, without considering his actual ability to bear it. In order to show the demeanor of the Supreme Kingdom of the Celestial Empire, Yang Guang "added military offices and swept the floors into soldiers" a few years ago, collecting all the soldiers from Shandong, Hebei and Henan, and at the same time recruiting tens of thousands of sailors from the south to establish a naval army. It is estimated that the total number of troops in this expedition reached more than 1.13 million, and the total number of people mobilized reached 30,000 to 4 million, which is unprecedented.
However, this expedition failed without achieving any results. The reason is objective: First, there are too many people, which is inconvenient for command. In the cold weapon era, combat is subject to the limitations of command capabilities and logistics supply. The more soldiers the better. If the number of people exceeds a certain limit, it will pose a huge challenge to command communication and logistics supply, and will eventually be dragged down by their own numbers. Second, the climate is very different and the environment is not suitable for the environment. Most of the soldiers of the Sui Dynasty came from the Central Plains and were extremely unacceptable to the cold weather in the north, which could easily lead to illness and loss of combat effectiveness. Third, the terrain is dangerous and difficult to march. There were many high mountains and ridges in Goguryeo, and it was extremely difficult to marches and provide food and grass. Especially after crossing the Yalu River, each soldier of the Sui army was asked to carry 100-day rations to march. The overwhelmed soldiers secretly buried the food in the ground, resulting in the lack of food in the later period and could not fight.
Subjective aspect: First, Yang Guang can't command but blindly command. He divided the entire army into 24 armies and marched in different ways, but did not arrange unified command, resulting in their respective combat and no joint force was formed. The second is to be suspicious of the generals and refuse to let go. Yang Guang asked the frontline generals to "report and report on any military advancement and not be proficient", but the opportunity for war is fleeting, so how could they wait for your imperial edict? The guards of Goguryeo often claimed to surrender when the city was about to be broken. When Yang Guang's imperial edict was asked for instructions, the other party strengthened the city again and had to fight again. The Sui army once had the first general of the Gao army, Yi Wenzhide, and had no way to advance and retreat. Yi Wenzhide expressed his willingness to surrender, but the front-line generals did not dare to take the initiative. When Yang Guang's instructions were conveyed to the army, Yi Wenzhide had already escaped and ascended to heaven. Third, the generals are greedy and arrogant and underestimated the enemy. After Hu'er landed in the navy, he had won a small victory, but then he was defeated by the enemy's plan to lure the enemy and his entire army was wiped out.
The consequences of the failure of the first Eastern Expedition were extremely serious. Not only did hundreds of thousands of troops be lost, especially the elite troops trained during the establishment of the Sui Dynasty were lost, but they also inspire domestic conflicts. The rise of civilians in China, laying the groundwork for the demise of the Sui Dynasty.
In 613 AD, Yang Guang, who was unwilling to fail, ordered the recruitment of 300,000 troops to be recruited in person. Due to the lessons learned from the last failure, he chose to be in charge of command of Liaodong this time, and ordered the generals to advance on land and land, and allowed to "do things cheaply." In this eastern expedition, everything went smoothly, and they conquered the city and reached the city of Pyongyang. Just as the Sui army was preparing to attack the city, Yang Xuangan, the second-generation official, rebelled in the country to avenge his father.Yang Guang urgently ordered the Eastern Expedition Army to return to the country to suppress the rebellion, but the Goguryeo army then pursued it, and the Sui army suffered heavy losses.
In 614 AD, Yang Guang, who was breathing a little during the civil unrest in the country, ordered his personal expedition to Goguryeo again. However, the war was not good at the beginning of this expedition. The soldiers recruited from all over the country fled in the middle and even joined the rebel army directly. Few people arrived at the front line on time. Fortunately, the navy led by Lai Huer and won a great victory and was ready to attack Pyongyang. At this time, Goguryeo was extremely weak due to years of fighting, so she sent envoys to ask Yang Guang to surrender. Yang Guang, whose vanity was satisfied, ordered him to withdraw his troops. Although he was unwilling to accept his wish, he had to obey the order.
Three Eastern Expeditions, and in addition to the reign of Emperor Wen of Sui, the famous general Gao Ying also led an army of 300,000 to defeat Goguryeo. He used more than 2 million troops in the past and then failed to take down the small Goguryeo, but it caused the domestic political turmoil and the rise of chaos, which directly led to the rise of Tang Dynasty and the demise of the Sui Dynasty. Later, Yang Guang wanted to launch the fourth Eastern Expedition, but he couldn't implement it because of the mess in the country.
Of course, it does not mean that the Sui army's combat capability was low. Due to the technical conditions at that time, it would be very difficult to siege operations in the cold weapon era without internal support, let alone expeditions from a thousand miles away. Later, the only time after ascending the throne, Li Shimin, led an army of 300,000 to conquer Goguryeo. There were also famous generals Li Ji, Hou Junji and others in the army, and they still returned in a disastrous defeat. Finally, during the reign of Emperor Gaozong of Tang Dynasty, after years of exhaustion of the enemy, General Li Ji and Xue Rengui led an army of 350,000 to pacify Goguryeo. According to this calculation, the troops mobilized before and after may be millions.
