A Republic That Shouldn’t Have Been Possible

Imagine a land surrounded by mountains, where the paths were so narrow that only one rider could pass at a time. Iga Province, during the chaotic Sengoku period, stood out not only because of its natural location but also for something even more unusual—it wasn’t ruled by any daimyo or powerful samurai. While the rest of Japan was drowning in feudal conflicts and power struggles, Iga became an unintended experiment in autonomy. A commune of shinobi, or rather, a people's republic.

At a time when other provinces were subjected to local rulers, and the common people were seen as insignificant in the eyes of samurai, a unique republic emerged here—Iga Sōkoku Ikki (伊賀惣国一揆, literally “Joint Revolt of Iga Province”), a collective of jizamurai (something between a farmer and a samurai), local farmers, and craftsmen who created a self-sufficient community, independent of external rule. Iga was the only place in all of Japan where equality among the residents prevailed, and decisions were made based on cooperation and mutual support.

But that wasn’t all. Iga was also the birthplace of one of the most mysterious and influential forces of that time—the shinobi. The ninja of Iga, instead of fitting into the hierarchical order of Japan, were its greatest disruption. The entire province was a thorn in the side of the daimyo, who attempted to conquer it many times, unsuccessfully. The treacherous terrain and the masterful tactics, which today we would call guerrilla warfare, exhausted every army. When Oda Nobunaga, a figure who needs no introduction, sent his son to break the resistance of Iga, he suffered a crushing defeat without even fighting a single regular battle. The province stood strong against the mightiest forces, despite being so small and lacking a centralized government or ruler, unlike other regions of Japan during the Sengoku era.

It was under these difficult conditions, with techniques of hiding in the forests, erasing tracks, setting traps, using smoke bombs, mastering the art of silent enemy elimination, and the perfect ability to camouflage, that the legendary school of shinobi emerged, later evolving into ninjutsu, and finally into the black-clad, masked ninja figures we know from popular culture.

How did the small, mountainous province of Iga resist the ambitions of the great daimyo? How did it maintain its independence? How was it organized, and what was life like for the people there? And finally—how did it give birth to the shinobi? Let's explore all of this in today’s article!

What Was Iga Before Independence?

In the heart of Japan, hidden like a lost treasure, lay the province of Iga—a small, rugged land surrounded by towering, nearly impenetrable mountains. These mountains were its greatest ally, serving as a natural barrier that protected it from enemy invasions for centuries. The paths leading to Iga were narrow and dangerous, so steep that only one horse could pass through at a time. To outsiders, it was a land cut off from the world, difficult to conquer and full of mysteries. To the residents—it was home, and its natural fortifications provided a sense of security that was often lacking in a Japan drenched in the blood of continuous warfare.

At a time when power in Japan shifted from one hand to another, and daimyo constantly fought for dominance, Iga witnessed an endless series of battles and conflicts. It was a time of chaos, where feudal lords fought for every scrap of land, and the poor inhabitants, whose lives held little value in the eyes of samurai, died either by the katana or from hunger amid scorched fields and villages.

Under these harsh conditions, a unique social structure emerged—the jizamurai (地侍, "land samurai"), local landowners who over time became not only wealthy farmers but also warriors. Initially, they were merely farmers granted samurai titles because there were no higher-born landowners in their region. These farmers were thus given the title of lower samurai (jizamurai) to defend their lands from bandits and invasions. Over time, their status grew. They were organized, well-armed, and deeply connected to the land they lived on, and most importantly, they could count on the loyalty of other farmers and craftsmen from their region, as they came from the same roots—jizamurai gradually, and almost silently, took control of the province.

Iga was a place where every family had to fight for its survival. The periods of Kamakura and Muromachi brought about anarchy, with a weakened central authority, and local daimyo struggled to maintain their positions. Iga, lacking an influential lord, became a battleground for rivalry between various clans. Villages were attacked by bandits, and local rulers, unable to provide protection, were forced to rely on the self-sufficiency of their communities. In other words, samurai who had privileges as lords over the people because they were supposed to protect them—failed to fulfill this duty. As a result, the people had to defend themselves. The samurai lords and their clans became unnecessary. Jizamurai, farmers, craftsmen, monks—they decided to take care of themselves.

The Kamakura and Muromachi periods were crucial for the formation of the warrior community in Iga. The central authority, scattered and weak, could not control these mountainous regions, allowing the locals to develop autonomous structures. The people of Iga, growing in strength, not only defended their land but also learned the art of war—not on battlefields, but in the dense forests, in the shadows of rocks, away from the enemy's sight. These were times when Iga, isolated and left to its own devices, began to earn the reputation of an impregnable fortress, where every resident could threaten the life of a trained samurai invader without even leaving the cover of the forest thickets.

The Organization of the "Republic" of Iga

During the chaos of the Sengoku period (15th and 16th centuries, nearly 200 years of permanent war between various daimyo in Japan), Iga became an independent and unconquerable bastion. The Iga Sōkoku Ikki (伊賀惣国一揆, "United Alliance of Iga Province") was not only a symbol of unity but also a masterful example of a quasi-republican military and social organization. Contrary to the widespread trend of submission to strong daimyo, Iga became an experiment in autonomy, where local jizamurai—farmers with samurai status, along with monks, craftsmen, and ordinary village residents—collaborated, creating a self-sufficient community, independent of external rule.

The main authority in the Iga Sōkoku Ikki rested in the hands of the Council of Elders (高齢者会議, Kōrei-sha Kaigi, literally "assembly of seniors"), composed of the most prominent jizamurai from various clans, such as the Hattori, Momochi, and Fujibayashi families. This council was responsible for making key decisions regarding the defense of the province, resource management, and maintaining internal order. Decisions were made through voting, with respect for every member's voice, ensuring a balance of power and minimizing the risk of one autocrat seizing control. Such a structure allowed for flexible responses to external threats and effective management of internal provincial affairs.

The central element regulating life in Iga was a set of rules established by the community around 1560. It was simply called "Okite," or a code of regulations. These rules, often passed down through oral traditions and informal codes, regulated cooperation between villages, the self-defense system, and laws concerning loyalty and punishment for betrayal. For example, the defense of the province was the responsibility of every resident, and betrayal of the community was severely punished, including confiscation of property and execution. Such regulations not only strengthened social unity but also created an atmosphere of mutual trust and responsibility, essential for survival during the turbulent Sengoku period.

One of the most important elements of Iga's organization was cooperation with neighboring clans, especially Kōka (甲賀). Relations between Iga and Kōka were complex and based on mutual interests in defense against external threats. The two provinces, separated by steep mountains, acted as allies, sharing knowledge, military strategies, and supporting each other when needed. Regular meetings on the border of the provinces were held, where issues concerning resource management, defense planning, and military coordination were discussed. This cooperation was crucial to maintaining the independence of both provinces and allowed them to successfully repel numerous attempts of conquest by more powerful daimyo.

The organization of Iga Province was a masterful combination of traditional feudal structures with innovative principles of grassroots self-governance. The Council of Elders and close cooperation with Kōka created a system that was not only effective in defending against enemies but also fostered the development of culture and community. This unique structure allowed the Iga region to become the most independent region in Japan. Its legacy, as we will discuss further, continues to inspire modern enthusiasts of history and pop culture around the world.

Life of the People in Iga

Life in Iga Province, surrounded by mountains and closed off from the outside world, was in essence similar, though somewhat different, from the rest of Japan. Villages scattered along the mountain slopes looked like small islands in a sea of dense forests, where the daily tasks of the inhabitants were as harsh as the landscape around them.

The climate and rugged conditions were an inseparable part of life in Iga. The terrain in which the inhabitants lived was not conducive to agriculture. Rice fields, although they existed, were difficult to cultivate due to the clayey soil, and crops suffered from a lack of irrigation. In winter, the mountains became impassable, and the freezing winds swept snow from the peaks, burying villages under a thick layer of snow. In such conditions, the residents had to find ways to survive—and they did.

Agriculture was the foundation of life, despite the difficulties that come with farming in such terrain. The families of jizamurai, though they generally held samurai status, often worked directly in the fields, supported by neighbors and their families. Instead of relying solely on rice, they cultivated various other crops, such as millet and vegetables, which were less demanding. Even children, just a few years old, learned basic tasks related to farming. They helped with the harvest, carried water, and sometimes took their first steps in martial arts. Each day was dominated by work, but equally important was the preparation for defense.

Training in martial arts was an inseparable element of life in Iga, from childhood to adulthood. Every young man who turned 17 automatically became part of the local militia (or perhaps better: communal defense), ready to defend the province from invasions. In Iga, there was no room for passivity. Boys and girls trained in martial arts, learning what we would call guerrilla tactics today—disappearing into the forest, hiding in the shadows, setting traps, and hand-to-hand combat. Each village had its own master, often an experienced jizamurai, who oversaw the training of young warriors. Shinobi techniques—from which the art of ninjutsu later evolved—were passed down from generation to generation. It was here, in the shadows of the trees and the rugged fields, that the stories were born, which later evolved into legends of the elusive ninja.

The Appearance of a Typical Village in Iga Reflected Its Unique Character

Narrow paths, winding between rice fields and forests, led to the central village squares, where the residents gathered to discuss social matters and plan defense. Smoke from the hearths rose above the huts, and in the distance, on the hills, small defensive outposts could be seen, which served as the first line of defense. These fortresses, though not impressive in size, were strategically placed, allowing for quick responses to threats. Their simple, wooden structures blended into the forest landscape, making them hard to detect.

The military spirit of the Iga community was almost palpable. Every man from 17 to 50 years of age was obligated to serve, but this wasn’t just a formality—it was part of every resident’s identity. From a young age, children were taught that their lives, land, and even freedom depended on their ability to defend it. This was not a province where war was rare. Iga lived in a constant state of readiness, knowing that at any moment, armies from daimyo, attempting to conquer their independent republic, could appear. The residents were not just farmers and craftsmen—they were warriors, and every day was a training session for the battle that would undoubtedly come, sooner rather than later.

Life in Iga Was Tough, But Filled with Pride and Independence

The inhabitants of this province didn’t submit to fate; they shaped it on their own terms, ready to fight for every patch of land. It was in these harsh conditions that a community was born, one that became legendary—not only as a land of farmers but as the cradle of ninja, spies, assassins, masters of adaptation, and survival.

We already know that the birth of the shinobi (ninja) culture in Iga Province was the result of extremely specific geographical, social, and political conditions that forced its inhabitants to adapt and develop unique survival strategies. Surrounded by mountains, Iga was a hard-to-reach place, which gave it a natural defensive advantage but also required its people to be self-sufficient and ready for defense. External threats—whether from neighboring daimyo or invasions—pushed the local community to develop advanced guerrilla and espionage tactics, which became the foundation of what we now know as ninjutsu. In other words, they had to learn how to fight against an opponent who far outnumbered, out-armed, and out-trained them. How could they fight in such conditions? By adapting.

The shinobi from Iga were not the mysterious warriors of legend, jumping across rooftops in black attire. In reality, they were masters of strategy, guerrilla tactics, and espionage, who skillfully used the terrain, knowledge of their opponent, and camouflage techniques. Their training didn’t just involve learning how to fight but deeply understanding tactics and the psychology of the enemy. Hattori Hanzō and Momochi Sandayu, the two most famous ninja from Iga, were masters of organization and strategy. Hanzō, who later served Tokugawa Ieyasu, hailed from Iga and was known for his exceptional planning skills and leading shinobi units in the most dangerous missions. Momochi Sandayu, on the other hand, was a master who trained successive generations of shinobi, introducing them to the art of survival and concealment.

Ninjas were more like special agents than warriors. Their tasks involved infiltration, gathering information, sabotaging enemy actions, and protecting their territory from invasions. Shinobi training began in childhood, and young ninjas had to go through rigorous trials, learning survival tactics, hand-to-hand combat, espionage, and camouflage techniques. In Iga, there was a principle known as Nuninseibai (抜忍成敗, literally "the punishment for a ninja who deserted"), which meant absolute loyalty—betrayal was punished by death. These rules were crucial in ensuring the unity and coherence of the province, which, though small, effectively resisted powerful samurai armies.

In truth, ninja were primarily defenders of their province. They served not their lord (there wasn’t one—the Council of Elders ruled), but above all, the community, whose safety depended on their skills. Unlike samurai, who fought according to the Bushido code, ninja were masters of direct combat, where flexibility, adaptation, and avoiding confrontation on an open battlefield played a key role. Their methods were subtle, quiet, and their most important task was to remain unnoticed.

The philosophy of the ninja was based on the principle that the art of shinobi is not for private use. Momochi Sandayu, one of the most important shinobi masters, taught: “The art of shinobi is not for private use, but in situations where there is no other choice, for the country, for the council, or to protect life.” Ninjas were not, in theory, mercenaries acting for profit but specialists who used their skills only as a last resort when all other means failed. They were the last line of defense in times of chaos when war, betrayal, and external invasions were daily threats.

Conflicts and Wars

The Sengoku era, full of chaos and continuous wars, brought to the forefront one of the greatest military leaders in Japanese history—Oda Nobunaga. He was a man of unwavering ambition, who undertook the monumental task of unifying the country. A great visionary and unifier, a psychopathic tyrant and narcissist—he has been described in various ways, but we will not delve into the history of this extraordinary personality today. It’s enough to say that his armies outnumbered and out-equipped every opponent, and his reputation spread throughout Japan.

However, even Nobunaga encountered people whom he could not easily crush and wipe out, as he had done with, for example, the Buddhist monks and the people they trained—Ikko Ikki (more on them here: ikko ikki).

There was a place that annoyingly and insolently resisted the grand plans of great lords—a small mountainous province called Iga. A place where the rules of daimyo didn’t apply, and its inhabitants defended their freedom and independence completely contrary to the hierarchy prevailing elsewhere in Japan at that time.

The First Tenshō Iga War (1579)

The first major conflict with Iga was initiated by Nobunaga’s son, Oda Nobukatsu, who, against his father’s will, decided to conquer the province. Supported by the betrayal of one of Iga’s residents, Shimoyama Heibei, who revealed the province’s weaknesses, Nobukatsu decided to restore Fukuchi Castle. It was meant to be a stronghold from which Oda’s army would subdue the rebellious inhabitants of Iga. However, the residents of this mountainous land, masters of guerrilla tactics, quickly learned of Nobukatsu’s intentions. Under the cover of night, the ninja of Iga—masters of infiltration and surprise attacks—went into action.

Fukuchi Castle, whose reconstruction was begun by Nobukatsu’s forces, was never completed. The people of Iga, using their mastery of guerrilla tactics, effectively disrupted Oda’s military operations. They attacked Nobukatsu’s forces at times when they least expected it, taking full advantage of their intimate knowledge of the terrain. Although there was no direct siege of the castle or a pitched battle, these actions were enough to frustrate Nobukatsu’s efforts and significantly deplete his army’s strength, ultimately forcing the son of the great Nobunaga to withdraw. The young Oda, embarrassed by his defeat, returned to his father, filled with justifiable fear of his reaction.

Oda Nobunaga did not tolerate failures. His outburst of anger must have been intense. His son was scolded but survived. As for Iga—Nobunaga saw only one future for it: total annihilation.

The Second Tenshō Iga War (1581)

Two years after the first war, Nobunaga could no longer tolerate Iga’s independence. This time, he personally led a massive invasion to finally crush the resistance of its inhabitants. Nobunaga’s army was a force to be reckoned with—it numbered about 40,000 warriors, including the finest samurai and the latest technological advancements, such as firearms (arquebuses). In contrast, only about 4,000 ninja and local warriors from Iga stood against them. But it wasn’t the numbers that would determine the outcome—it was the terrain.

The shinobi of Iga were not going to fight an open battle. Hidden in the mountains, forests, and concealed valleys, they began a guerrilla war, using every rock and tree as their tools. They attacked suddenly, retreated even faster, and their actions were so swift and quiet that before Nobunaga’s samurai could react, they were already losing men. The ninja’s mastery of hiding, setting traps, and launching surprise attacks sowed chaos among the ranks of Nobunaga’s powerful army.

Perhaps we would like the story to end differently here, but unfortunately, history is unforgiving. Even the most refined guerrilla tactics could not ultimately stop Nobunaga’s powerful and well-organized forces. His army gradually took over the land, destroying one stronghold after another. When the ninja of Iga were forced to defend their last fortresses, like Hijiyama and Heirakuji, the province’s fate was sealed. Temples and villages burned, and the lands of Iga were drenched in blood as Nobunaga personally oversaw the destruction of the republic. Kashiwara was the last fortress to fall, and with it ended the epic resistance of the inhabitants. Oda Nobunaga once again did what he did best—he annihilated them all.

After the Fall

Those who managed to survive fled from Iga, beginning a new chapter in their history. Among the surviving ninja, many found refuge in other provinces, serving powerful lords such as Tokugawa Ieyasu. Hattori Hanzō, the famous shinobi commander, went down in history as the one who later helped Ieyasu escape from his enemies, leading him through the mountains of Iga. Though the province was destroyed, the legacy of the ninja endured—their tactics and survival skills became legend, and their abilities found new uses in Tokugawa’s service.

Oda Nobunaga triumphed, but the spirit of the Iga ninja lived on—in philosophy, martial arts, and secrets passed down through the centuries.

After the fall of the Iga republic in 1581, the lives of the ninja from this province changed dramatically. Although their territory was destroyed by Nobunaga’s army, and the province itself was incorporated into his domain, the ninja of Iga did not disappear from history. On the contrary, many of them found new places in the world, serving various feudal lords, particularly the Tokugawa clan, which, as we know, changed the course of Japanese history.

After the War—The Role of the Iga Ninja in Tokugawa’s Service

One of the most famous episodes in the history of the ninja after the fall of Iga was their support for Tokugawa Ieyasu, the future shogun, who, during the chaos following Nobunaga’s death in 1582, had to flee from Sakai to his domain in Mikawa. The ninja from Iga, under the command of the legendary Hattori Hanzō, helped Tokugawa lead his troops through the mountainous terrains of Iga, ensuring his safety and enabling him to reach his destination. This episode, known as Igagoe (伊賀越, literally "The Crossing through Iga"), became famous as an example of the loyalty and effectiveness of the ninja in the service of the Tokugawa clan. Thanks to this help, Ieyasu survived the crisis after Nobunaga’s death and eventually united Japan.

After Tokugawa’s successful escape, the ninja of Iga earned prestige and trust in his eyes. When Ieyasu became shogun and established the Tokugawa shogunate in Edo, many ninja from Iga were incorporated into his personal guard. However, their role changed—from fighters and masters of guerrilla warfare, they became guards, spies, and special agents, ensuring the shogunate’s security and monitoring its enemies.

Hattori Hanzō gained fame as the commander of the Edo Castle guard, and the ninja of Iga became part of an elite formation responsible for protecting the shogun’s palace and family. Their espionage skills were used to monitor the activities of feudal clans that could threaten Tokugawa’s power. However, their military role gradually diminished, as the Edo period was characterized by relative peace, reducing the need for traditional military actions.

Legacy and Modern Iga

Though the Iga republic was brutally destroyed by Oda Nobunaga’s army in 1581, the legacy of its residents, particularly the ninja, survives to this day. Modern Iga, part of Mie Prefecture, remains a living monument to this unique history. Today, instead of battlefields and fortresses, you’ll find a ninja museum, which attracts tourists from around the world. This place offers a fascinating glimpse into the real skills and techniques of shinobi, separating myths from facts and emphasizing the important role ninja played not only in the history of Iga but of all Japan.

Each year, Iga hosts ninja festivals, where both locals and tourists can experience shinobi culture. Parades march through the streets, and acrobatic displays and combat performances showcase skills inspired by ancient techniques. It’s not just entertainment, but also a way of preserving a heritage that has been closely tied to the region for centuries. These festivals have become a symbolic bridge between the past and the present, and the people of Iga proudly cultivate their unique history.

The heart of modern Iga is the city of Ueno, where a reconstruction of Ueno Castle, the former symbol of the region’s strength and defense, stands. Today, Ueno is a popular tourist destination, attracting people who want to understand how unique this community was. The castle and the ninja museum, located nearby, are central points on the map for lovers of Japanese history.

In recent years, Japan has seen a revitalization of ninja culture as part of its national heritage, with pop culture, especially Naruto, playing a significant role. Modern Iga has become a symbol of this revival, not only as a tourist destination but also as a bearer of values that have endured for centuries. With growing interest in Japan’s history and tradition, the legacy of the Iga ninja has become a lasting monument to their resilience, innovation, and mastery of the art of survival.

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 A connoisseur of Asian culture with a deep-seated appreciation for various philosophies of the world. By education, psychologist and Korean philologist. By heart, an Android developer and an ardent tech aficionado. In tranquil moments, he champions a disciplined way of life, firmly believing that steadfastness, perpetual self-enhancement, and a dedication to one's passions is a sensible path for life.

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