I promise I didn’t start out this year with some apologetic agenda related to historical commanders that the world considers losers. While it might appear that way, I swear, that wasn’t the plan. Truth is, I don’t have much of a plan at all when it comes to scheduling, drafting, and then recording these posts. I simply write what seems to come naturally.

That said, and as many of you are aware, I did recently return from a week’s worth of historically-themed day trips that left me with, perhaps, more inspiration than I could readily process. Since two of those three trips centered upon the ground campaign of the Imjin War—Hideyoshi’s invasion of Joseon Korea in 1592—I’ve actually come away with new insight into how it could have all gone the way it did. How the Joseon king’s military elite could fail him again and again and again, giving the war the shape it eventually took.

These two trips focused on the first few weeks of the war, after the initial invasion at Busan and subsequent battle of Dongnae, but before Konishi Yukinaga’s troops entered the abandoned defenses of Seoul. This was the period during which the king and his court completely misunderstood the military situation, launching a counterstroke that had little if any real chance of actually stopping the advancing Japanese.

We began by traveling down to Sangju where the first real field battle took place. The Battle of Sangju resulted in 600 Joseon “troops”—the vast majority of whom had only seen a single day’s experience in the army—being overrun by a much larger force of battle-hardened invaders. The Joseon commander, General Yi Il, had been sent south of the narrow and heavily fortified Saejae pass with the mission of delaying the enemy long enough for his commander, General Sin Rip, to man that vital chokepoint.

Yi Il arrived in Sangju on June 2nd, 1592 after being hastily dispatched south from the capital at Seoul. Leading some 60 professional cavalrymen, Yi Il augmented his ranks by opening up the state granary in Sangju and paying peasants to join his force. Some 540 apparently did so and Yi Il led them north across a small stream to a position sprawling two hills. Konishi Yukinaga’s lead elements made quick work of the rabble and Yi Il abandoned both horse and armor in a mad retreat north over the pass.

To us today, knowing the outcome of the battle, his decision to stay there and fight seems abjectly silly. Better by far to take those 600 men—most of them civilians just earlier in the day—and man the south facing ramparts at Saejae. In that way he might have held long enough for Sin Rip and his 6,000 men to fall in behind them on the second line of fortifications which spanned the narrow pass. This might have drastically changed the first stage of the war as Yukinaga would have been forced to assault the successive fortified lines guarding the pass, a process that would have taken time and caused casualties. The vanguard Japanese general could really afford neither.

Instead, Yi Il’s nascent army was crushed where it stood at Sangju, for no discernible benefit whatsoever to the nation’s defense. This is THE definition of military failure, right? Not just sacrifice, but meaningless sacrifice.

Yet walking the tiny battlefield, I arrived at a very different perception of Yi Il’s embarrassing performance that fateful June 3rd. You see, I left out a couple things above in my historical retelling of the story. There are things that we know now that neither Yi Il nor Sin Rip could possibly have known then, and they greatly affected how things transpired.

First, there were supposed to be trained garrison troops at Sangju, though the records are unclear on how many. These were supposed to be the army Yi Il would use to delay the invaders. Unfortunately for him, however, that force had been ordered to defend the regional capital at Daegu and so were already gone by the time the general arrived. This was, no doubt, a serious disappointment to Yi Il after his hasty ride south from the capital. Still, the record indicates he attempted to adapt and overcome, seeking a way to quickly raise troops to replace the men he’d lost to another commander.

Second, Yi Il had little in the way of military intelligence and relied only upon historical precedent regarding rates of march over and through the Taebaek Mountains separating him from Busan. Thus, Yi Il thought he had at least a week to train his men. Now, that might not seem like much, but for a Korean peasantry already familiar with the army’s primary weapon, a composite bow with an effective range of 300 meters, it probably didn’t seem to Yi Il like he was attempting something impossible. Yet in reality, Yukinaga’s lead elements rolled over his tiny force only a day after their mobilization, with a speed quite beyond anything Yi Il could have ever imagined.

Third, neither Yi Il nor most of the rest of the Joseon army had ever faced effective volleys of firearms before. That the Japanese had such weaponry was known, but the only analog by which Joseon’s military elite could consider their effect in battle were the much more primitive weapons used by the Ming Chinese. And, frankly, they weren’t impressed. That the Japanese firearms—copies of Portuguese Arquebuses—could outrange the Korean bows would have been simply unbelievable to Yi Il and his peers. They’d just never before encountered such effective firearms before and so had no idea what to expect. They’d soon learn, of course.

Finally, Yi Il had no idea of the size of the force heading his way. That Konishi Yukinaga alone led some 18,700 men across the beach at Busan was utterly lost on him. That Yukinaga’s vanguard division was backed by another 30,000 men under Kato Kiyomasa and Kuroda Nagamasa, advancing on separate axes would have been beyond his reckoning. Yi Il no doubt thought he was facing a larger version of the deep ranging pirate raids that occasionally plagued his kingdom. By the time he realized he was facing a highly motivated, hard marching, well trained, and deeply experienced force commanded by a battle-hardened samurai commander … well … it was simply too late. And the 600 men who stood with him that day were mown down like grass.

Yi Il, like so many military generals throughout history, fell victim to the unknown. Not in the sense that something mystical slew his men. Rather that the old axiom to “Know what you know and know what you don’t know” was as true then as it is today. More often than not, it’s the information you don’t know—forcing military leaders to assume the most logical—that trips you up.

In Yi Il’s peculiar case, nothing that man “knew” to be true actually was. The army he was sent to command was gone by the time he got there. The time he thought he had to raise another force was off by a factor of seven. The enemy’s weaponry was much more effective than he could have ever possibly imagined. And the size of the opposing force was so much larger than he’d ever envisioned. All of this combined led to the deaths of 540 civilians under arms and 60 cavalrymen that would be sorely missed later in the campaign.

Yi Il didn’t know what he didn’t know. He simply couldn’t conceive of a battle and battlefield beyond his own experiences along the northern border and the assumptions those experiences led him to make. While this battle, Yi Il’s cautionary tale from the Sixteenth Century, warns of the need for effective military intelligence, it also holds a lesson for life in general.

How often are we led astray by our assumptions? How many times have we made a bad decision for lack of a single piece of critical information? That one thing that we know—just KNOW—would have made us choose a different, perhaps more successful, path? I know I’ve been there.

It’s a difficult tightrope to walk, actually, between taking council of our fears—something General Patton warned his men to avoid. And trying to account for all the things in a given situation that are truly unknown. Yet that enumeration, that identification of the unsolved-for variables, can often help us make better decisions. Can help us to better know what we don’t know … and plan accordingly.

The Battle of Sangju, representing the supreme failure of long-serving General Yi Il, offers another reminder to us as well. That the results of a given battle, or event in history, is not all there is to a story. That what we see today as the unbelievable decisions men make while under duress often were made for the best of reasons and intentions.

Yi Il didn’t set out to lose his entire force a day after he took command. And if any, much less all, of his reasonable assumptions had proven correct, it might have been a different story. He had deployed on good, defensible ground after all, with a ridgeline to his rear and a water obstacle to his front. Textbook, really. And yet, Sangju is known still today as a military disaster—one which led to another, greater catastrophe at Chungju just a few days later.

Still, it’s important to note that the battle happened the way it did not due to any lack of effort by the one man responsible to take action that day. Rather, due to his inability to adapt to a situation changing far faster than he realized. To be clear, it was still an embarrassing failure. To be fair, it was one his commander would repeat less than a week later.

M. G. Haynes