Events of the past week have really put an exclamation point on just what a tumultuous year it’s been in Northeast Asia.  A year of accusations, threats, and sanctions, both official and net-inspired.  And that’s just looking at Japan and the Republic of Korea!  Still, through all the ugliness of the past twelve months it can be really easy to forget that once upon a time, in a land … well … right here, these two countries were not only close, but were, in fact, military allies.

Now, before anybody gets bent out of shape, let me qualify that statement.  At the time of which I speak, neither Korea nor Japan had fully unified.  Japan was in its Yamato Period (roughly 250-710 AD) and the central state really only exercised control over Northern and Central Kyushu as well as the southern half of Honshu islands.  Centralized control by the Yamato aristocrats was tenuous at best, but it constituted the seeds of what would become a real Japanese government and state.

The Korean Peninsula was divided at the time into three kingdoms plus a small confederacy of settlements in the south.  Goguryeo ruled north of the Imjin River up into parts of Manchuria.  Silla ruled roughly the eastern half of the peninsula generally south of the Han River.  Baekje ruled the western half of the peninsula generally south of the Han.  And Gaya—called Minama by the Japanese—existed as a loose confederation of states along the coast struggling and eventually failing to survive between the two southern giants.

These three Korean kingdoms fought each other and invading Chinese armies throughout the “Three Kingdoms” period of Korean history (roughly 57 BC to 668 AD).  And just like in modern times, these states found it desirable and even necessary to form alliances with each other and outside powers in order to survive, prosper, and hopefully, gain control over the entire land settled by Korean-speaking peoples. 

As with any such time of endemic warfare, alliances shifted back and forth over time with the rough result that only minor changes were effected geographically.  Eventually, however, there appears to have been a settling of sides, so-to-speak, with Silla allying with the newly established Tang Dynasty in China, and Baekje becoming quite close to the Yamato state in Japan.

“How close?”  You might ask.  Close enough that the King of Baekje sent princes to be raised in the Yamato court.  Ancient documents being what they are, there remains to this day a debate over whether or not the princes in question were diplomats or hostages with the former more popular in Korea and the latter more so in Japan.  That said, archaeological evidence as well as what follows historically, would seem to support an interpretation of extremely friendly relations between Yamato and Baekje.

Exactly when Silla and the Tang Chinese developed their strategy to knock out one rival Korean kingdom after another is unclear but a military tsunami struck the coast of Baekje in 660 AD in the form of 130,000 Chinese troops.  At the same time a Silla army 50,000 strong drove westward like a dagger, the two allies effecting a pincer movement aimed at the Baekje capital of Sabi.  With the larger Chinese threat looming, only 5,000 Baekje troops could be spared to hold the mountain passes to the east, and these were brushed aside with ease by the much larger Silla force which continued its march toward Sabi. 

Finally, with both allied forces joined together, Sabi was besieged and taken with great loss of life, Baekje reportedly losing 10,000 men in its desperate defense.  King Uija of Baekje formally surrendered in 660 AD, and this should have been the end of the story, the end of the Kingdom of Baekje.  Yet far more interesting events would close out this chapter in Northeast Asian history.

You see, Baekje had, upon realizing the gravity of the threat, sent for help to its only ally … Yamato Japan.  The Yamato state had no desire whatsoever to see its only partner on the Asian continent ground to dust.  And so Crown Prince Naka no Oe (later the Emperor Tenji) dispatched a relief army to assist in the defense of Baekje.  Given the speed of communications and bureaucracy at the time, Yamato forces arrived well after the fall of Sabi, but Baekje General Gwisil Boksin had been fighting a war of resistance more-or-less on his own since the fall of the capital and the Japanese intent was to link up with his army and expel the invaders.

Between 661 and 663 AD some 32,000 Japanese troops arrived in Baekje and, once consolidated, made their move.  Boksin’s force had been cornered in the city-fortress of Churyu and Yamato moved to relieve the siege and join forces with the beleaguered rebels.  The tactical problem was one of geography, the Geum River had to be crossed in order to reach the rebel Baekje army.  This, the Yamato force set out to do, never anticipating the catastrophe awaiting them.

The Tang fleet wisely positioned itself in the river to block any such intervention.  Since the Japanese fleet greatly outnumbered the enemy, however, the Yamato forces pressed on to conduct what amounted to a contested river crossing.  Over the course of the two-day battle Chinese lines buckled several times, but apparently never broke and the army of Yamato failed to reach its allies.  Baekje cavalry had, in desperation, apparently attempted to assist the river crossing with a foray of its own, but this too was repulsed and the attempt was abandoned.  Churyu surrendered a week later and the Kingdom of Baekje was forever relegated to the history books.

Losses at the Battle of Baekgang, as it’s called, are difficult to gauge, but contemporary sources hint at it being Japan’s greatest pre-modern military defeat.  Japanese sources indicate only half the army returned to Japan, but they weren’t alone.  Large numbers of the Baekje aristocracy escaping persecution, skilled craftsmen who refused to work for their enemies, and ordinary villagers seeking a better life, put their trust in long-time allies, and accompanied the army back to Japan.  They brought with them both their own and borrowed Chinese culture, religion, bureaucracy, and writing, greatly contributing to the renaissance that would soon transform Japan’s ruling central authority and way of life.

Operationally—as mentioned during a previous post—this experience caused great distress among Yamato’s elite.  Concerned that a combined Tang-Silla force would follow the retreating force back to the island of Kyushu, Japan culled stone-masons from Baekje’s refugees and set them to work building the first stone-lined fortifications in Japan’s history near Dazaifu.  How could they have known that the Tang-Silla conspiracy was focused on uniting the Korean Peninsula, successfully conquering the northern state of Goguryeo in 668 AD?  As well, they likely had no idea that they were—utilizing Korean craftsmen and techniques, of all things—laying the cornerstones, so-to-speak, for an art form that would a millennium later come to symbolize Japan and the deep ties to its long history.

This was the beginning of the end, you might say, as the expedition to Korea left a sour taste in everyone’s mouth.  The victorious Kingdom of Silla would never forget—even as it was busy unifying Korea under one rule—that military intervention by nearby Japan had nearly wrecked the whole thing.  China would similarly bear in mind for a long time that any attempt to establish rule over, or at least stability among, its eastern neighbors would have to take into account a third, nearly unreachable party.  But for Japan, the fear that Korea was, as German advisor Major Jacob Meckel observed much later, “a dagger pointed at the heart of Japan,” would never quite go away, leading indirectly but surely to Hideyoshi’s invasion of Joseon Korea in 1592 and all that followed in the 19th and 20th Centuries.

Sure, the animosity between Korea and Japan that we see today does indeed have long, ugly roots.  That said, what lies beneath—if one chooses to dig far enough—is a spirit of cooperation, trust, and even alliance.  

It may be that history has a sense of humor.  I can see a certain similarity between the geo-political situations in the 7th Century and today, characterized by a rising China and untrustworthy “other” Korean state.  Once again, Japan and the Republic of Korea would—from a purely objective point of view—seem to have more to gain by banding together against shared threats than standing apart.  What’s the old saying, those who refuse to stand together are doomed to fall separately?

Most of those who oppose such a union—beside those with Chinese and North Korean accents, of course—do so on the grounds of history, citing an assumed, basic incompatibility between the two cultures.  This vignette, however, makes abundantly clear that is simply not the case—that the two nations continue to have much more in common than they have separating them.  Regardless, then as now, the decision to pursue either cooperation or antagonism is always a matter of politics and policy … and sometimes a stubborn, resolute determination to set aside differences in order to address the greater threat to both nations.

M.G. Haynes 

* The great period map is attributed to: By SY - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=61409525.