Imagine a military manual that is just so strategically
brilliant that it fundamentally revolutionized
an entire nation's defense. offered by a royal
prince who was infamous for these terrifying,
murderous rampages. Right, a really dark history.
Exactly. And now imagine that despite its massive
historical impact, like exactly zero physical
copies of this masterpiece exist anywhere in
the world today. Literally a phantom text. It
is a complete phantom, yet we know precisely
what is written on every single missing page.
Welcome to the Deep Dive. Glad to be here. For
you listening today, our mission is to explore
the Muya Sinbo, which is the new compendium of
martial arts published in Korea in 1759. Yeah,
we are unpacking a historical mystery today that
feels honestly like a true crime thriller crossed
with a martial arts epic. It really does, because
the contradictions surrounding this text make
it one of the most compelling documents in military
history. Oh, absolutely. I mean, we are looking
at a text that totally redefined 18th century
combat. right? But it was born from the mind
of a deeply troubled ruler, and then it just
completely vanished from the physical record.
It's just gone. Right. But to understand the
sheer magnitude of what this missing 1759 manual
accomplished, we really have to look backward
first. OK, let's unpack this. Yeah, because the
Korean military didn't just wake up one day and
decide to you know, meticulously catalog their
combat techniques for the sake of scholarship.
Right. They weren't just bored in a library.
Exactly. They were forced into it by sheer survival.
We need to set the stage with the catalyst for
all of this frantic military organization. And
that would be the Imgen War, right? Stretching
from 1592 to 1598. Yes. This was just a catastrophic
conflict for the Korean National Army. I mean,
they were caught entirely off guard by the invasions.
Which exposed some pretty fatal flaws. Oh, systemic
fatal shortcomings. in their national defense.
Their existing military structures, their troop
formations, and their tactical playbooks simply
crumbled against the realities of this specific
conflict. Wow. Yeah. The devastating losses forced
King Ciancio, who ruled during this period, to
initiate these sweeping military reforms. He
realized they needed a completely new approach
to training and combat. So this is like a professional
sports team getting absolutely crushed in the
playoffs, realizing their entire foundational
strategy is totally obsolete and completely rewriting
their playbook based on the team that just beat
them. That's a great way to put it. Or in this
historical case, looking to the allies who stepped
in to help. Right, exactly. So following the
Imjin War, King Seon -jo ordered his military
leadership to adopt the successful training models
of a renowned Chinese general named Kiji Guang.
Okay. And they synthesized these foreign tactics
into a foundational text. This was published
in 1610, and it was called the Muyebo, which
translates to martial arts illustrations. Martial
arts illustrations. Yeah. And this manual distilled
their new tactical doctoring into six highly
specific foundational skills. Right. And rather
than just listing these weapons, Paint a picture
for us. Like, how did these six skills actually
function together on a 17th century battlefield?
Well, they operated as a tightly coordinated
unit, really engineered to counter enemy infantry.
So first, you had the Dune Pei. The Dune Pei.
Right, which is a large shield used by soldiers
at the very front of the formation. They were
there to absorb the initial shock of an enemy
charge. Got it. And right behind them stood soldiers
wielding the Naxian. This is a fascinating weapon,
translated as a thorn spear. A thorn spear? Wait,
so like... Yeah, it wasn't just a pointy stick,
it was a multi -branched pole arm, literally
covered in iron thorns. Oh, wow. The goal was
to actually entangle and trap the enemy's swords
in the branches. Okay, so the shield bearer takes
the hit, the thorn spear traps the attacker's
weapon, and then what? Then the offensive line
strikes. You had soldiers with the jang chang,
which is a traditional long spear, and they would
deliver the fatal thrust from a safe distance.
Right, while the enemy is tangled up. Exactly.
And for closer, heavier engagements, they utilize
the Dengpa, a three -pronged spear designed to
catch a blade and instantly counter -strike.
It sounds so systematic. It was. And rounding
out the unit, you had the Ganbong, a heavy long
staff for blunt force trauma, and the Song Sudo.
a massive two -handed sword. Two -handed, so
really heavy. Very heavy. It was capable of breaking
right through enemy pole arms through sheer kinetic
energy. It's basically an interlocking machine,
like every weapon covers the vulnerability of
the weapon next to it. Precisely. But I have
a question here. If they already completely overhauled
their military playbook and perfected this interlocking
machine in 1610, why did they need to invent
a brand new one a century and a half later? If
we connect this to the bigger picture, military
strategy is a living, breathing entity. Right.
What worked flawlessly in 1610 was a massive
leap forward at the time. But, you know, warfare,
metallurgical technology, and cultural exchanges
continually evolve. The enemy adapts. Always.
Enemies adapt to your interlocking machines,
so you must adapt again. By the time we reached
the 18th century, specifically the reign of King
Young Jo from 1724 to 1776, those six original
skills simply weren't sufficient to handle the
diverse threats of the era. New combat environments,
new weapons. Exactly. The military desperately
needed an expansion. Which brings us directly
to the author of our phantom manual, the Moya
Senbo. And this is where the story shifts from,
you know, military logistics into something much
darker. Yeah, it takes a really grim turn. Because
the author tasked with this expansion was King
Young Jo's heir apparent, Prince Sato. Right.
Prince Sato is an incredibly complex and frankly,
tragic figure. In 1759, he takes the initiative
to compile the Moyes and Go. He's the one who
adds to it. Yes. He retains those six original
skills from the 1610 manual, but he conceptualizes
and adds 12 entirely new skills to the curriculum.
It dramatically expands the King's military repertoire.
Yet the historical record regarding Prince Sado's
personal life is horrifying. It really is. We
aren't talking about a disciplined stoic scholar
quietly writing in a palace library. The sources
detail that Prince Cerdo suffered from profound,
severe mental illness. Oh, very severe. This
manifested in horrific, unpredictable, violent
outbreaks. He was known to randomly kill and
assault people within the palace walls. Yes.
I mean, he was a daily terror to the very people
he was theoretically preparing to defend. It
creates a staggering historical paradox. On one
hand, you have a mind succumbing to chaotic,
violent impulses, destabilizing the entire royal
court. Right. But on the other hand, that same
mind possessed the rigorous mathematical focus
required to meticulously categorize, organize,
and expand a highly technical system of martial
arts. It's so hard to grasp. We often struggle
to reconcile such destructive madness with such
constructive genius in a single historical figure.
And his actions eventually crossed a line where
the kingdom could no longer look away or manage
his illness. Yeah, the situation became entirely
untenable. The threat he posed to the stability
of the state was so extreme that his own father,
King Young Cho, was forced into an unprecedented
and tragic decision. Just a brutal outcome. Very.
In 1762, merely three years after Prince Sado
compiled this vital revolutionary martial arts
manual, he was executed by suffocation. He's
only 27 years old. 27. I mean he drafts the blueprint
for their entire national defense and three years
later he is executed for his madness at 27. It's
a tragic timeline. But the ultimate twist of
this entire saga is the fate of the book itself.
Yes. The Moisimbo, this brilliant compilation
born from tragedy, it just does not exist. Not
a single physical copy has survived to the modern
day. It is entirely lost to history. Which naturally
presents modern historians with a massive problem.
Right, and here's where it gets really interesting.
I have to express some heavy skepticism on behalf
of you listening right now. Okay, let's hear
it. If there are absolutely zero surviving copies
of this book, how can any historian definitively
state what was inside it? Like, is the academic
community just making educated guesses? That's
a fair question. Are they just looking at the
weapons of the era and filling in the blanks
of what an 18th century prince might have written
down? It is a vital question to ask any time
a historian makes a definitive claim about a
missing primary source. But what's fascinating
here is the methodology. It is not guesswork.
OK, so how do they do it? Historians utilized
a rigorous process of historical reverse engineering.
It's effectively a process of subtraction using
the text that do survive on either side of the
missing manual. Walk us through that mathematical
deduction. How do we read the shadow of a missing
book? Well, we established our timeline. We know
the 1610 manual, the Ouijaibo, contained exactly
six skills. That is our starting point. Right,
the shield, the thorn spear, the six. Exactly.
Now we jump forward past our missing 1759 book
to a highly comprehensive manual published later
in 1795. This one is called the Muidobotamji.
Okay, so 1795. And we have intact copies of this
1795 text. It contains exactly 24 martial systems.
So we have six skills in 1610 and 24 skills in
1795. Yes. And the historical records from 1795
explicitly state what new elements were being
added to the curriculum at that specific time
to reach the number 24. Oh, so they documented
the new additions. Exactly. The 1795 manual focused
heavily on adding horseback techniques. It took
four existing weapons. The flag spear, the twin
saber is the moon knife in the flail. and created
specific disciplines for wielding them from the
saddle. Got it. They also added general horsemanship
and a polo -like game. That is six new equestrian
focus additions. Okay, let me do the math here.
So we take the 24 total systems from the 1795
book. Right. We subtract the six original skills
from the six tier 10 book. We are down to 18.
Then we subtract the six horseback and polo skills
that we know for a fact were added in 1795. And
what does that leave you with? That leaves exactly
12 skills unaccounted for. Exactly. Those 12
remaining skills are the precise additions made
by Prince Sano in 1759. The Mui Simbo forms the
exact, mathematically perfect, missing puzzle
piece bridging the two surviving texts. That
is incredibly satisfying to realize. Right. We
know the contents because we can isolate the
exact variable that changed between the 17th
and late 18th centuries. It completely validates
the entire premise of the text. So since we know
exactly what these 12 missing skills are, let's
look at the actual martial arts techniques Prince
Sato was codifying. The terminology he chose
is vital here. Prinzano originated the term sipal
-gi, which translates to the 18 fighting methods
or 18 warriors tools. 18 fighting methods? Yeah.
This encompasses the six original skills plus
his 12 new additions. But the number 18 wasn't
just a coincidence of the math, was it? Not at
all. The number deliberately mirrors the established
Chinese concept of the 18 arms of Wushu. Oh,
interesting. Yeah. Prinzaforta was purposefully
structuring the Korean military curriculum to
parallel a highly respected, deeply historical
Chinese martial framework. He systematically
classified these 18 skills into three distinct
categories of bodily mechanics, thrusting, slicing,
and striking. Let's dive into the fascinating
variety of those 12 new skills he added. I mean,
he includes the jupjungsang, which is a long
bamboo spear, and the gichang. Right, the flag
spear. Yeah, a spear heavily weighted with a
flag attached to confuse the enemy's vision.
But the blade variety is where you really see
how highly specialized their combat environments
were becoming. The environmental adaptation is
brilliant. You can see how weapons were tailored
not just for open battlefields, but for highly
specific tactical scenarios. A perfect example
from the sources is the yado. It's described
as a sharp sword featuring a single edged blade
about three feet long utilized with one hand.
Yeah. But the key detail is who it was issued
to. It was favored by foot soldiers and specifically
by sailors. Right, naval combat. Because if you
are fighting in the incredibly cramped, chaotic,
rigging -filled space of a ship's deck, you literally
cannot swing a massive two -handed sword. You
need a fast, agile, one -handed three -foot blade
to navigate that claustrophobic environment.
It is pure pragmatism. On the other end of the
spectrum, for open field combat where reach and
momentum dictate survival, the manual introduces
heavy pole arms. Like the Waldo? Yes, the Waldo
or Moonblade. This is a massive pole arm topped
with a wide curve blade that relies on sweeping
circular mechanics. It directly parallels the
Chinese Guandao. And right alongside that Chinese
-style weapon you have the Haiyapdo, or spear
blade. Exactly. This is another polearm, but
its narrower, swifter profile parallels the Japanese
Nachinada. Right. But out of all the 12 editions,
the mechanical ingenuity of the Seng Jiong, the
Twin Swords, really stands out. Oh, the Twin
Swords showcase a deep, deep understanding of
combat efficiency. because you are fighting with
two identical blades, one in each hand, but they
were specifically manufactured with flat inner
profiles so they could be carried together securely
in a single sheath. Right, one scabbard. So a
soldier draws once in one fluid motion and instantly
has two weapons deployed. The design reduces
the time from resting state to full combat readiness
by half. It's brilliant engineering. But looking
at this whole list, a Chinese style moon blade
a Japanese -style spear blade, specialized naval
swords, the twin swords. The analogy that comes
to mind is open source coding. Open source coding.
I like that. Break that down. Well, Prince Sato
isn't limiting his military by saying, we will
only use weapons invented within our own borders.
No, not at all. He is looking at the entire regional
theater of war like a developer looking at a
global code repository. He observes the Japanese
spear blade mechanics. He analyzes the Chinese
curved blade physics He takes traditional native
Korean swordplay and he compiles all of it into
the ultimate updated hybrid operating system
for his military He really takes the best features
from everyone exactly, but you know This raises
an important question though regarding national
identity house armies are historically very proud
often conservative institutions There was an
inherent tension between ruthlessly adopting
for technology to survive and maintaining your
own distinct cultural heritage. Ah, I see. The
manual highlights this tension beautifully by
juxtaposing two specific sword disciplines. Right,
the Admiral's sword versus the National's sword.
Exactly. The Muya Simbo includes the Jadok Jium,
the Admiral's sword. These were techniques directly
introduced by a Chinese admiral named Li Ruosong.
who fought alongside the Koreans during the Imjin
War. Admiral Lee's system utilized straight bladed
swords with a single edge for slashing, combined
with double edged maneuvers for stabbing. The
Korean manual preserves this foreign influence
meticulously, dedicating 14 specific stances
entirely to this Chinese discipline. They didn't
let pride get in the way of what worked. They
watched a foreign admiral win battles on their
soil, so they copy -pasted his exact stances
into their national playbook. They did. But immediately
alongside the Admiral's sword, Prince Susato
makes a point to include the Bongguk Geom. which
translates directly to the national sword. Balancing
it out. Exactly. The manual explicitly stresses
the ancient traditional Korean origins of the
Bonggukjeom. It deliberately contrasts the deep
native roots of this system against the more
recently adopted foreign techniques of the Admiral's
Horde. It's the ultimate psychological balancing
act. They are fiercely protecting their sovereign
identity while simultaneously holding the very
foreign weapons they need to guarantee that sovereignty.
Well said. We should also mention that the 18
methods weren't purely weapons based. Prince
Sato significantly expanded their unarmed combat
systems, the Guanbup. He did. He returned to
the foundation by the 16th century Chinese general,
Qi Jiguang, who originally documented 32 unarmed
methods. Princeda's curriculum identifies and
refines about 19 of those original Chinese methods,
but then integrates 14 entirely original methods
of his own. This yielded a highly sophisticated
33 method unarmed combat system. And to complete
the 12 editions, the manual includes the Pyongan,
a jointed flail paralleling the Chinese two section
staff. The mechanics of a flail are terrifying
on a battlefield. I mean, it relies on angular
momentum to generate massive force. And the jointed
chain allows the striking end to literally bend
around an enemy shield to crush the person holding
it. Right. It completely defeats the very purpose
of the shield we discussed in the 1610 manual.
Oh, wow. Yeah, it does. It just shows the continuous
arms race of military evolution. So that gives
us the full picture of the phantom manual, the
Seppelgi. 18 skills, 6 old, 12 new, forged from
the trauma of invasion, formalized by a brilliant
but violent prince, executed for his madness,
and then reverse engineered centuries later by
historians. It's an unbelievable journey. But
this 1759 blending of cultures didn't just stay
trapped in the 18th century, did it? It directly
dictates how martial arts are understood today.
It does. If you examine modern Korean martial
arts, the term sip pal gi, those 18 fighting
methods, has undergone a fascinating linguistic
shift. For the general public, it has become
a broad, generic catchall term. The sources equate
it to how the term kung fu is often used in the
West. People use it colloquially to just mean
martial arts, completely unaware that they are
referencing a highly specific 1759 military curriculum.
However, while the terminology has broadened
in popular culture, there are small, intensely
dedicated groups of modern practitioners who
use the term sipalji in its strict historical
sense. Like historical reconstruction. Exactly.
They're engaging in active historical reconstruction.
So they are essentially doing what Western historical
martial arts groups do with medieval broadsword
manuals. They are reading the surviving texts,
analyzing the stances, the footwork, the precise
weapon dimensions, and trying to pull these movements
off the page and back into the physical world.
That's right. They're trying to breathe life
back into the Phantom Manual. So what does this
all mean? I have to ask a Ship of Theseus style
question here. If the unbroken mass to student
teaching lineage was shattered centuries ago,
and the original 1759 physical manual itself
was destroyed, is the modern reconstructed martial
art truly the same martial art that Princess
Otto designed? That is the defining question
of any historical reconstruction. Does a modern
practitioner execute a strike with the yetto
down to the exact millimeter that an 18th century
sailor would have? Right. Likely not. But knowledge
is most valuable when it is applied. The underlying
mechanics of the moon blade, the geometric leverage
of the twin swords, the 14 stances of the admiral
sword. Those concepts survived. The ideas survived.
Yes. The fact that a modern individual can read
the surrounding literature, grasp the physics,
and physically reconstruct the biomechanics of
these strikes proves that the knowledge transcended
the physical paper. The art is still breathing.
The paper burned, but the mechanics survived
the fire. Exactly. For you listening, let's briefly
recap the incredible journey we've mapped out
today. We began with a devastating systemic failure
in the 1590s, forcing a traumatized military
to adopt a six skill playbook to survive. A desperate
measure. Right. And a century and a half later.
An intellectually brilliant but dangerously unstable
prince named Sato expands that playbook into
18 distinct fighting methods. He pulls from Chinese
and Japanese influences to compile a masterpiece
of hybrid defense. Truly hybrid. The prince is
executed, his manuscript manishes, and yet...
Through the mathematical deduction of historians
and the physical sweat of modern practitioners,
those 18 ancient skills have been pulled back
from the void. It is a profound testament to
how interconnected and remarkably resilient human
history is. It truly is. But before we let you
go, I want to leave you with one final provocative
thought to mull over on your own. Earlier, when
we were discussing how historians reverse engineered
the missing manual, we noted that the later 1795
manual added horseback weapons to the curriculum.
Right. They added the mounted use of the spear,
the sabers, the moon knife and the flail. But
they also officially added a polo -like game.
A recreational sport was formally integrated
into a lethal national defense curriculum. That's
a great point. I want you to consider the implications
of that. How much of what we view today as ancient,
rigorous, life or death warrior training was
actually just adapted from the elite sports and
recreational games of the era? Where exactly
is the line between a soldier's preparation for
war and an athlete's pastime? Think about that
the next time you watch a modern sporting event.
Thank you for joining us on this deep dive. Stay
endlessly curious and we'll catch you next time.