I love history. Most of you, by now, are all too aware of that fact. But I love it for what may, at times, seem to be odd reasons. Sometimes I revel in the scope of it all, history is, after all, the story of humanity, and thus a colossal subject growing—quite literally—by the minute. Often I find myself fascinated by linkages I never suspected were there. Occasionally I get consumed by some bizarre factoid that I never knew existed, even in a subject I thought I understood. Every once in a while, however, I’m completely dumbstruck by the sheer irony that emerges from the historical record.

Fukuoka, a city on the northwest coast of Kyushu island in western Japan, has for me fallen into that latter category. Fukuoka is a lovely, modern city, home to the best yakitori in all of Japan amongst many other culinary fascinations! As well, Fukuoka hosts multiple historical sites to include Fukuoka Castle, Dazaifu (former administrative center), Genko Borui (wall the Japanese built to repel the Mongols in 1281), and more ancient shrines and temples than can easily be counted.

The city is best known historically, perhaps, for nearby Hakata Bay, where the first Mongol invasion of Japan took place in 1274. This surprise attack, ordered by Kublai Khan, caught local Japanese forces by surprise and resulted in the destruction of much of the nearby metropolis then known as Hakata. That the invaders, a mixture of Mongol cavalry and newly-allied Korean infantry, felt more secure on their ships than on the ground surrounded by enemies, led to their destruction in a vicious storm, saving Kyushu and Japan from further depredations that year.

The young Kamakura Shogunate learned from the experience and was far better prepared the second time around, amassing and maintaining a large army in the area. The men were kept busy—and presumably out of trouble—constructing a 20 kilometer wall along the coastline to aid the defense. Parts of this wall remain today, though it takes some imagination to visualize the fortification as it would have appeared then. The second Mongol invasion attempt in 1281 struck Hakata Bay as well but never really made it past the fortification . . . the Mongol, Korean, and Chinese survivors of the many skirmishes being drowned or simply dispersed in yet another seasonal storm, later named the kamikaze, or “god wind”.

All too aware of this local history, I happily took time to visit Hakata Bay, walking along and photographing as much of the old wall as peeked above the shifting sands and urban development. The crudely built fortification had done its job and then been abandoned when it became clear the Mongols would not return. A little further East, I traced the sloping walls of Fukuoka Castle, noting that many of the stones used to erect the walls in 1601 had been taken from the crumbling Genko Borui. I made my way out to Dazaifu, long the administrative capital of Kyushu and site of the impressive Dazaifu Tenmangu Shrine constructed in the year 905. A great day in total, and as the sun began to set I was so satisfied with my newly acquired perspectives on Japanese historical sites that I nearly missed one—and it turned out to be the most interesting of all.

Ono Castle was constructed, incredibly, in the year 665, two years after Japan’s failed attempt to support the Kingdom of Baekje at the Battle of Baekgang. The alliance which destroyed that southwestern Korean state was formed between the Korean Kingdom of Silla and Tang Dynasty China, a military partnership that would go on to finish off the third Korean Kingdom of the era, Goguryeo, within three years. In the ensuing decade, Silla would fight vigorously to evict their former Chinese allies, unifying the entire Korean Peninsula under one ruler for the first time in its history.

In 665, however, that future was far less certain. This was especially true for the first real centralized government in Japan’s history, the Yamato. Misunderstanding Silla’s long-term goals, and having just lost some 10,000 men and hundreds of ships attempting to help their only continental ally, the Yamato Government found itself suddenly on the defensive and fearing a combined Silla-Tang invasion of Kyushu.

That this invasion never happened is a matter of history. That it was never truly contemplated is clear from the rapid and coordinated reorientation of Silla and Tang forces toward Goguryeo, leading to that state’s demise in 668. All the same, a crown prince and future emperor of Yamato Japan funded the construction of Ono Castle, fortifying the heights above all-important Dazaifu. In fact, the fortification made use of nearly the entire mountain, resulting in eight kilometers of stone-clad walls, constructed in a manner very unlike any other fortress in Japan.

Missing from Ono Castle is the usual alteration of the natural terrain that preceded castle construction everywhere else in Japan, giving Japanese castles their characteristic appearance. Gone too were the fantail masonry corners that make Japanese castle walls so uniquely elegant. What remained was an attempt to turn the mountain itself into a fortification, with nearly vertical, dry-walled masonry walls which followed the natural terrain in a manner that was—dare I say—clearly Korean. Not the latter Korean construction most visitors see at places like Namdaemun or Suwon. No, I mean the early walls constructed during the three kingdoms period. And there in the failing sunlight above Dazaifu, THAT’S what Ono Castle suddenly reminded me of!

Frantic searches online in the hotel that evening ran well past midnight—yes, I know I’m not normal—and brought me to multiple Japanese websites touting Ono Castle as perhaps the first demonstrated use of stone in the construction of a Japanese fortification. Several sites mentioned a flood of refugees streaming into Kyushu from the toppled Kingdom of Baekje during the time period in question. Finally I tripped across indications that stonemasons formerly in the employ of the kings of that fallen Korean state, had been hired to gird Ono Castle in stone, literally laying the foundation for what remains there today . . . some 1,354 years later!

Japan would, over the course of the next 500 years, take that basic knowledge of masonry and apply it to the successive ring, defense-in-depth concept that had governed Japanese earth and wood fortification design from the very beginning. Japanese masons would learn over time to make their walls more resistant to the earthquakes that plague their country, a problem all but absent on the Korean Peninsula, resulting in the fantail design that today characterizes Japanese castles.

What emerged from that period of learning and adaptation is clearly evident in the 12th century ruins at Oka Castle and 13th Century Bitchu Matsuyama Castle. The ultimate development would, of course, be the gorgeous and expansive fortifications of the 14th-16th Centuries that are now so recognizable, many of which still stand today, a testament to Medieval Japanese engineering. Himeji, Kumamoto, Matsumoto, Osaka, the list goes on-and-on, but they all owe their provenance to a group of refugee stonemasons fleeing the violent destruction of everything they considered home. In a very real sense, then, the iconic Japanese castle design was essentially an unintended by-product of a once-strong alliance between Yamato Japan and Baekje Korea.

Considering all that has happened since—and the state of affairs in Northeast Asia today—I can’t help but feel humbled by history at times like this. That such a site was so near and I was almost too lazy, too busy picking low-hanging historical fruit, as-it-were, to find it and visit, bothers me, an unapologetic, if obsessed, fan of history. That these two peoples were once so closely related is undeniable. Once again, it’s simply a matter of historical record. That something so fundamentally Japanese as their unique castle design was built upon the transmission of technology from—of all people—refugee Korean castle workers in the wake of a failed bilateral defense . . . well . . . that’s simply amazing. And truly ironic.

M. G. Haynes