Korea has awarded the title “The Great” to only two kings in its history. And there is an appropriate symmetry between the two. The later Great King, Sejeong of Joseon, was the philosopher king, wise ruler and inventor, creator of the Korean alphabet. The other, Gwanggaeto of Goguryeo, the great expander of territories, the victor of many battles and one of the first to unify- however temporary- the peninsula, was the warrior king.
Gwanggaeto assumed the throne in 392. Goguryeo was already experiencing a revival thanks to the reforms of the previous king Sosurim. But the kingdom still had scores to settle with their enemies in the North, the Yan dynasty of the Murong Xianbei, and their enemies in the South, Baekje.
Almost immediately after becoming king, Gwanggaeto seized Baekje’s fortresses in a push towards the south. He took over Gwanmi fortress, an important location just north of the Han river. The loss caused turmoil within Baekje and the kingdom’s King Jinsa ended up being either deposed or killed in a hunting accident (anyone familiar with East Asian history knows that there is no contradiction between the two, and “died in a hunting accident” is usually a synonym of a coup in the palace). Baekje’s next king, Ansin, tried to take back the fortress but failed. This would be the beginning of a long series of conflicts between Ansin and Gwanggaeto, with the latter always emerging victorious.
The next big battle between Baekje and Goguryeo was in 395 at a location named Paesu river. Baekje was defeated. Not being one to give up or learn a lesson, Ansin attempted another attack in the 11th month of the year, but his troops were stopped by a snowstorm. Another year, another attack. But this time Gwanggaeto not only defeated Ansin’s troops, but forced the Baekje king to sign a treaty, a treaty heavily in the favor of Goguryeo. Things were set to be stable, until in 399 Gwanggaeto received a distress call from his only ally in the south: Silla.
Silla had been watching Baekje’s growing power with concern. The alliance between Baekje, Gaya, and the Wa of Japan was a major threat to Silla, and the king sent an emissary in 392 to Goguryeo in hopes of forming an alliance of their own. After Baekje’s humiliating defeat and treaty, the kingdom called upon its allies and attacked Silla. Gwanggaeto responded, and the joint Baekje-Wa-Gaya army lost the battle. In the year 400, Baekje and Gaya were subdued, and Gwanggaeto’s troops stayed behind in Silla. The Wa and Baekje tried successive attempts at warding Goguryeo, but it was futile at that point. The influence of Goguryeo over the peninsula meant the first time a single power occupied the region which would later be called Korea.
Gwanggaeto’s influence would reach far beyond that. While moving southward, the king was also engaged in a series of campaigns in the north, sometimes within the same year as a Baekje attack. He fought against the Yan dynasty, and at a certain point the Yan split into smaller kingdoms, one of which, Northern Yan, was ruled by a descendant of one of the Goguryeo hostages that the Murong Xianbei had taken off with earlier. The king, Go-un, recognized Goguryeo as the parent country and formed a peace treaty. Gwanggaeto then took over Eastern Buyeo- because at this point, why the hell not?- which meant that by the time Gwanggaeto died at the age of 39, no doubt from sheer exhaustion caused by all the campaigns, Goguryeo had reached a size that would never be rivaled by future Korean dynasties again.
Goguryeo after Gwanggaeto and his son Jangsu were done. Source: Wikipedia
Gwanggaeto and his campaigns are the stuff of legends. Korea today, looking to a past where the country was stronger, more powerful, still romanticizes the warrior king in a series of novels, legends and TV shows. The cult around Gwanggaeto, however, started almost immediately after his death. Spearheaded by his son, King Jangsu, a steele was built in 414 to honor Gwanggaeto’s exploits. This stele, a giant monument recounting the reign of Gwanggaeto, is located so far north outside of current Korean borders that later generations assumed it belonged to a king from another country. It was only in the 19th century that the stele was rediscovered, and with enormous consequences.
The steele starts off with the founding myths of Goguryeo- from Jumong to Daemusin– and then about the wars Gwanggaeto fought and won. The controversial line describes the state of the southern peninsula in 396, and the stele says something along the lines of “the Wa crossed the sea and occupied Baekjan (a derogatory word for Baekje) and Silla.” This gave credibility to the Imperialist project of 19th century Japan, which had claimed that Korea during the three kingdoms era was part of Japanese territory, a claim they used to justify their occupation. Scholars to this day still grapple with the inscription and the meaning behind it, They have come up with many theories in the following years.
The Stele. Source: Wikipedia
One of the earlier response was, typically, to create a conspiracy theory. The argument was that the stele inscription concerning Wa’s invasion was a forgery, inscribed in the 19th century by Japanese archaeologists. This theory has gone into disrepute, since no evidence of tampering has been found. Another theory argues over semantics, or rather syntax. The subject of the sentence “crossed the waters,” they say, does not refer to Wa, since the phrasing of the sentence is a bit obscure and some words are missing. Instead, Goguryeo is the subject of the sentence. This is yet more proof of the epoch-making importance of grammar. Award for most imaginative justification has to go to the theory, apparently popular in North Korea, that there were actually two three kingdoms (six kingdoms?): one set on the peninsula, and the other on the Japanese islands. So, the theory says, Wa invaded Silla and Baekje of Japan, not Korea. Right.
Probably the most popular theories these days explains it this way: Jangsu engaged in a bit of hyping and myth-making. This is not entirely implausible, considering the stele itself. The monument refers to Gwanggaeto’s rule with its own era name, Yeongnak (Eternal Pleasure). Era names were the privilege of emperors, who, mostly from China, were the ones who got to name the calendar of their rule, and other countries usually followed the same era name. So, it seems that at Gwanggaeto and Jangsu’s time, Goguryeo saw itself as an empire. And empires have historically always used stories to legitimize the expansion of their power. Imperialist Japan would ironically use the stele to engage in the same tactic in the 19th century. So, while it’s known that the Wa did live in the peninsula, as they had trading posts around the region, it would make sense that those trading posts were seen as threats the region, and a legitimate excuse to invade. Baekje and Silla, the weaker nations, needed the strong power of the Goguryeo Empire to protect it from the Wa invaders, the stele seems to be telling us.
Who knows, maybe the army of Goguryeo expected to be greeted as liberators by the people of Baekje and Silla.