History of KoreaⅡ. The Three Kingdoms Develop into Centralistic Nations3. The Expansion of Silla and Goguryeo’s Wars with the Sui and Tang of China

B. Goguryeo’s Victory over the Sui and Tang

The Sui, which had unified China after a prolonged division of over 350 years, threatened Goguryeo that it would be in their best interest to serve Sui. Goguryeo, however, sought an alliance with the tribe of Dolgweol (Turks) northwest of Sui. Sensing an attack from the Sui, Goguryeo made a bold advance assault on the Liaoxi region, which could serve as the military base for Sui (598).

The Sui emperor, Wen Ti (581~604), who had unified China, launched a retaliatory attack on Goguryeo, with a force of 300,000. The army crossed over the Liao River and attacked the boundaries of Goguryeo, while the naval forces crossed the ocean and closed in against the capital of Goguryeo. Goguryeo, however, easily defeated the invading force and the Sui Dynasty, which suffered a calamitous defeat, faced great difficulties both at home and abroad.

Yang Ti, the next Sui emperor, who ascended the throne after killing his father, proceeded to mount an invasion of unprecedented magnitude against Goguryeo, putting the fate of the nation on the line. The emperor himself commanded the battle, leading a huge force of 1.13 million (in 612).

Goguryeo, whose population stood at a mere 3 million, defeated the Sui forces thanks to the brilliant tactics of Ulji Mundeok, a famed Goguryeo commander (in what is known as the “Battle of Salsu”).

Another assault by Sui to bring down Goguryeo occurred in 614 A.D., but this, too, ended in defeat. What crumbled was not Goguryeo, but the war-weakened Sui empire.

The Tang dynasty (618~907) succeeded the fallen Sui. Immediately following its establishment, Tang called for Goguryeo’s surrender and made frequent military threats. Goguryeo tried its best to avoid war. However, war with Tang was inevitable as Tang attempted to conquer Goguryeo and incorporate the nation into Tang’s territory (known as the Goguryeo-Tang War).

The seeds of the war between Goguryeo and Tang had its origins in the greed of Tang to vindicate its honor for the defeat of Sui and to build a world empire. In 645, Emperor Tai Tsung himself led the army and invaded Goguryeo. However, Goguryeo defeated the huge Tang forces thanks to the meticulous tactics of General Yang Man-chun at Ansi Fortress in southwestern Manchuria, as well as cooperation from the civilian population. In one battle, Emperor Tai Tsung was hit with an arrow by the Goguryeo army. He suffered massive defeats in all three attempts at invasion.

Goguryeo was able to resist the repeated aggressions of Sui and Tang thanks to the solidarity and outstanding strategies of the Korean people. The war eventually led to the downfall of the Sui empire. The national strength of Goguryeo was also seriously weakened by the continuing wars. The victory of Goguryeo represents the historic triumph of Korea over China, one that safeguarded the territories of Baekje and Silla as well.

Notable Personage in History

The Hwarangdo Spirit of Silla - Sadaham

During the reign of King Jinheung (540~576) of Silla, there was a young aristocrat named Sadaham. He was appointed to the hwarang, an elite unit of young men. When he was about 15 or 16 years old, he was looking for an opportunity to serve his country. Sadaham volunteered to enlist in the war with the Gaya state. He fought well and made great contributions in the war effort.
Following the war, the King rewarded him with a large portion of land and slaves. Sadaham, however, freed the slaves after giving them the land. He said that he fought to serve his country, not to receive rewards. This garnered the admiration of the people.
Sadaham, however, had a great worry. His best friend was fighting for his life from wounds suffered in the war. His friend eventually passed away and Sadaham, too, followed him. The people of Silla eulogized Sadaham in great grief.
The hwarang of Silla valued friendship, pledged allegiance to their nation, and practiced bravery in battle. They were the source of strength for the development of Silla and the consequent unification of the Three Kingdoms by Silla.
Goguryeo defeats the Sui forces
Victory in the battle at Ansi Fortress