The Surprising Pirates of Sengoku Japan

In Japanese history, nothing is ever as it seems at first glance. Take pirates, for example—we imagine wild marauders, racing through the waves with swords in hand and fire in their hearts. Yet today’s story about the kaizoku, Japanese pirates and "people of the sea," reveals something entirely different. The Murakami clan, Japan’s most famous pirates, were renowned not only for their battles and maritime strategy but also for their refined poetry. In their world, piracy was an art, and the sea was a stage where they combined brute force with subtle elegance. As we’ve come to expect from Japanese history, there are no simple answers or easy judgments—even when it comes to pirates.

By comparison, when we speak of the wakō (倭寇, wōkòu), pirates we discussed a few weeks ago, the image aligns more closely with what one might expect. These were cosmopolitan adventurers—a mix of Japanese, Chinese, and Korean individuals—who spread terror from the coasts of Japan to China and Korea. They were ruthless, energetic, and lawless—embodying wildness, freedom, autonomy, and cruelty. However, the kaizoku of the Murakami clan, truly Japanese pirates, had a completely different identity. They were rooted in the samurai ethos of honor and loyalty, cultivating a tradition of the warrior’s code alongside a well-rounded education. Their activities were neither anarchic nor chaotic—they were a meticulously organized system based on strategy and maritime administration.

Today, we will explore this extraordinary history. The kaizoku (Japanese pirates) of the Murakami clan were not only guardians and sailors but also poets who composed renga and tanka. We will journey to the turbulent waters of the Seto Inland Sea to uncover their fortresses, understand how they controlled trade, and form our own opinions—were they pirates, guardians, or entrepreneurs?

The Seto Inland Sea: The Murakami Theater of Operations

The Seto Inland Sea (瀬戸内海, seto naikai, lit. "Sea among straits") is a region full of contrasts: at first glance, its waters may appear calm, almost languid, but this is mere illusion. Hundreds of islands and islets, scattered like pearls between Honshū, Shikoku, and Kyūshū, conceal secrets and stories that have shaped Japan’s destiny for centuries. It was here that the maritime empire of the Murakami clan was born, and these waters were not only trade routes but also the stage for great battles and political intrigue. The Geiyo currents—the strongest in Japan, sometimes exceeding speeds of 10 km/h—served as a natural barrier that could not be crossed without exceptional navigational knowledge. For unprepared sailors, they could be a deadly trap, but for the Murakami kaizoku, they were allies, tools of war, and natural protection.

The Geiyo Islands, such as Noshima, Innoshima, and Kurushima, became strategic pirate bases, forming a maritime fortress that was impossible to bypass. Each island was not only a natural lookout point but also a shelter for their flotillas. On hilltops, castles were built—coastal fortresses that allowed control over the most important waterways. Noshima, the headquarters of the main branch of the clan, was impregnable. Its stone walls and fortifications rose high above the waves, and from the observation towers, Murakami sentries watched for any approaching fleet—be it enemy or ally.

These fortresses, however, were not solely defensive bastions. They served as administrative centers where decisions about fleet operations were made, tolls for passing ships were established, and orders for naval convoys were issued. The Murakami were not ordinary pirates—they were masters of organization and logistics. There was no room for spontaneous chaos or chance. Each fortress was part of a larger network that controlled not only the waterways but also local communities that depended on trade and fishing. Their influence stretched from the port of Akamagaseki in the west to the gates of Sakai in the east.

Thanks to this network of fortresses and their knowledge of treacherous currents, the Murakami kaizoku earned their reputation as the undefeated "lords of the seas." No one could pass through the Seto Inland Sea without their knowledge, and those who tried to bypass their outposts risked losing their goods—and their lives. In this way, the Geiyo Islands became not only the center of their power but also a symbol of the Murakami’s military and political genius.

Murakami as "Lords of the Seas"

The Murakami clan, called kaizoku, or "pirates" (海賊—"sea thieves"), were not a monolithic group but consisted of three main branches: Noshima, Kurushima, and Innoshima, named after the islands that served as their operational bases. Each of these branches operated semi-independently while collaborating within a unified system that turned the Seto Inland Sea into their own "maritime kingdom." Thanks to the strategic placement of their islands, the Murakami controlled key waterways, and their fleet could swiftly respond to any attempt to breach their domain. Their power was so significant that even the strongest daimyō sought alliances with them—or tried to avoid their wrath.

The Murakami Domain

The Murakami clan (村上) was one of the more influential samurai families, whose power was built not on land but on the waters of the Seto Inland Sea. Their origins trace back to the Heian period, and according to tradition, they descended from the powerful Murakami Genji clan (村上源氏), a branch of the imperial family. This lineage allowed the Murakami clan to boast an aristocratic heritage. In later centuries, they focused on maritime activities, giving them a unique character among samurai families. Their headquarters were located on the Geiyo Islands, such as Noshima, Kurushima, and Innoshima, which served as their operational bases and centers of power. The Murakami not only controlled key waterways but also gained a reputation as masters of naval strategy, combining traditional samurai discipline and ethos with the practical management of a maritime empire.

During the Sengoku period, although they were formally samurai—loyal to powerful daimyō like the Mōri or Ōuchi clans—their methods resembled a more organized group of "maritime entrepreneurs," whose actions were not always legal and could be interpreted as piracy.

The Murakami Domain: Formal Control and Informal Influence

The Murakami domain was divided into two levels: formal territories under their direct control and informal spheres of influence that covered vast stretches of the Seto Inland Sea. In their formal domain were islands, ports, and fishing villages, which served as their primary operational bases. These territories were managed with the precision of the best administrators, implementing systems of taxes and regulations that facilitated the growth of local communities in exchange for their loyalty. For example, Futagami Island was a formal part of the Murakami domain—its inhabitants, primarily fishermen and salt producers, paid tributes in the form of seafood, timber, and rice, and were also recruited to work in support of the fleet.

The informal domain of the Murakami was much more extensive, relying on the reputation of their strength and networks of connections among "people of the sea"—fishermen, sailors, traders, and dock workers. For instance, the port of Akamagaseki, while not formally under Murakami control, fell under their unofficial influence due to relationships with local administrators. In every port frequented by ships, it was known that no goods could pass through the waters of Seto without the knowledge or consent of the Murakami.

Murakami as Navigators and Administrators

The Murakami clan was renowned not only as warriors of the sea but also as masters of navigation and administration. Their detailed knowledge of the treacherous Geiyo currents, considered the strongest in Japan, made them indispensable maritime guides for anyone attempting to traverse the perilous waters of the Seto Inland Sea. Narrow straits, shifting winds, and currents exceeding speeds of 10 km/h posed a deadly trap for inexperienced sailors, but for the Murakami, they were a natural advantage. They could expertly exploit these conditions both in naval battles and while escorting merchant ships, offering their services as guides for an appropriate fee. Without their support, ships risked not only losing their cargo but often their crews as well.

Managing Coastal Settlements: Examples of Hiburi and Futagami

The Murakami were also excellent administrators, skillfully managing both the islands within their formal domain and a network of coastal settlements. A prime example is the small island of Hiburi, where they implemented a detailed code regulating the daily lives of its inhabitants. In one preserved document from 1576, the Murakami explicitly required that all ships entering the port obtain approval from the Port Council and that any items found on the shore, such as shipwrecks or drifting wood, be reported to the authorities. These rules were designed to control trade and maximize the island's resources while ensuring order and stability.

An even more complex situation existed on Futagami Island, where residents lived under the dominance of various branches of the Murakami clan for years. Before 1582, the island was jointly governed by Noshima and Kurushima, who competed for influence. The residents of Futagami, primarily fishermen and salt producers, were required to pay tributes in the form of seafood, firewood, and other goods. After Noshima seized control of the island in 1582, new laws were introduced that prohibited residents from taking independent actions, such as self-organized ship protection or trade without Murakami approval.

Taxes, Trade, and the Exchange of Goods as Tools of Domination

The Murakami developed a complex system of taxes and fees that were critical to their dominance over the Seto Inland Sea. Ships passing through their waters were required to pay 帆別銭 (hobetsusen)—a "passage fee." In return, they received protective flags 過所旗 (kasho-ki) bearing the Murakami clan's crest, which guaranteed safe passage and protection from other pirates. This system was so effective that even merchant ships from China and Portugal sought these flags, recognizing their value and necessity.

The Murakami also leveraged control over the production and trade of goods. On Futagami Island, for example, they enforced the provision of products such as dried seafood, salt, and timber, which were then used to maintain their fleet. These goods were also traded in larger ports, such as Itsukushima, where the Murakami held significant influence.

Taxes, however, were not the only source of income—the Murakami actively participated in maritime trade. They managed a network of ports and trade hubs, collecting fees from passing ships and offering trade escorts. One example of their influence was Shiwaku Island, known as an important trade hub.

Unrivaled Maritime Administrators

Balancing the roles of pirates and guardians of the sea, the Murakami created a unique administrative system that included both efficient management of coastal settlements and control over trade routes. Their knowledge of currents, navigation skills, and superior organization of trade and taxation made them not only the "kings of the sea" but also masters of governance in a challenging maritime environment. Their influence was so extensive that no ship could feel secure in the Seto Inland Sea without their consent.

Organizational Strength

The Murakami’s activities extended beyond trade and taxation—they also offered maritime escorts that ensured ships reached their destinations safely. They were experts in navigating the treacherous Geiyo currents, making them indispensable guides. Their fleet consisted of fast and maneuverable ships called kobaya and larger vessels capable of transporting goods and engaging in naval battles. Because of this, rather than being viewed solely as pirates, they were regarded as "guardians of the sea," maintaining order on the waters in exchange for a fee.

It was this combination of military strength, exceptional organization, and strategic thinking that made the Murakami true "Lords of the Sea." Their domain, both formal and informal, was not just a network of influence but a mechanism of control that allowed them to transform the Seto Inland Sea into their own indivisible maritime kingdom.

Kaizoku Murakami as Poets and Educated Men

The Murakami clan, while known as "lords of the sea" and masters of maritime strategy, also stood out for their extraordinary culture and education, making their group even more remarkable. Contrary to the stereotypical image of pirates as unrefined marauders, the Murakami were well-educated individuals with deep roots in Japanese artistic and literary traditions. Poetry was a particular passion of this clan, and their works reflected their spiritual lives and erudition.

Poetry and the Renga Ceremony

One of the most notable expressions of their love for literature was the composition of renga (連歌)—linked verse poetry created during ceremonies where participants added one verse at a time, building a collective narrative. The Murakami organized renga sessions at the Oyamazumi Shrine (大山祇神社), revered by sailors and warriors as sacred. These poems were often dedicated to protective deities to ensure success in maritime expeditions and battles. Renga became not only a form of prayer but also a way to emphasize their education and prestige. The verses they composed combined homage to the natural beauty of the Seto Inland Sea with their personal experiences as "guardians of the sea."

Education and the Samurai Tradition

The Murakami were also considered well-educated in the spirit of the samurai ethos. As a samurai clan, they placed great emphasis on education, including knowledge of classical literature, calligraphy, philosophy, and military strategy. Their worldview extended beyond mere survival and enrichment—it blended elements of spirituality, loyalty, and artistic creativity. The clan’s poets and thinkers often drew inspiration from the landscapes of the Geiyo Islands and the turbulent waters of the Inland Sea.

Horaku Renga: Poetry in Honor of Deities

A unique aspect of Murakami literary tradition was Horaku Renga (法楽連歌), or "offering poetry." These were poems dedicated to deities, offered in shrines in exchange for protection and blessings. At the Oyamazumi Shrine, a spiritual center of the region, the Murakami organized ceremonies during which such verses were recited and documented. Through these practices, the clan reinforced their status as protectors not only of the seas but also of spiritual and religious values.

Their education and passion for poetry contributed to their reputation as not only invincible on the seas but also exceptional in intellectual realms. This unique combination of strength, sophistication, and literary prowess made the Murakami legendary figures that transcended the boundaries of the stereotypical pirate image.

Murakami as a Military Force

The Murakami clan, known as the "lords of the seas," gained fame not only as administrators and sailors but also as masters of maritime strategy, whose actions influenced the outcomes of major conflicts during the Sengoku period. Their military history is a tale of great victories, painful defeats, and complex relationships with powerful patrons such as the Mōri, Ōtomo, and Kōno clans.

The Battle of Miyajima (1555): Victory Through Maritime Strategy

One of the most memorable moments in Murakami's history was the Battle of Miyajima in 1555, during which the clan played a crucial role in the Mōri clan's victory over the powerful Ōuchi clan. The war was fought for control of the strategically located island of Miyajima, home to the famous Itsukushima Shrine with its iconic red torii gate that appears to float on water.

In this battle, the Murakami utilized their naval expertise and intimate knowledge of the treacherous Geiyo currents to secretly transport Mōri Motonari's forces to the island under the cover of night and storm. Their fleets anchored near the island, enabling the landing of troops who launched a surprise attack on the Ōuchi forces. Thanks to this strategy, the Mōri army captured Miyao Castle, and over 4,700 Ōuchi soldiers were defeated. This success was a turning point in the history of the Mōri clan, which, with the Murakami's support, became one of the dominant powers in the Chūgoku region.

The First Battle of Kizugawaguchi (1576): Triumph Against Oda Nobunaga

Two decades later, in 1576, the Murakami once again demonstrated their value as maritime strategists during the first Battle of Kizugawaguchi. The Murakami fleet, led by Takeyoshi Murakami's eldest son, Motoyoshi, supported the Mōri clan in their fight against Oda Nobunaga, who sought to cut off supplies to the Hongan-ji fortress in Osaka.

The Murakami employed an innovative tactic involving small, agile vessels capable of effectively attacking Nobunaga's larger ships. Their thorough knowledge of maritime currents allowed them to surprise the enemy, breaking the blockade and delivering supplies to the besieged fortress. This victory was one of the Murakami's greatest triumphs, and their tactics were later described in the famous war treatise "Murakami Naval Battle Principles" (村上舟戦要法, Murakami Shūsen Yōhō).

The Second Battle of Kizugawaguchi (1578): Confrontation With "Iron Ships"

Two years later, in 1578, the Murakami faced Nobunaga's fleet again during the second Battle of Kizugawaguchi. This time, however, their opponent was Kuki Yoshitaka, commander of Nobunaga's navy, who introduced a new weapon to the battlefield: ironclad ships (鉄甲船, tekkōsen). These massive vessels, covered in iron plates, were nearly impervious to the arrows and projectiles that constituted the primary weaponry of the Murakami fleet.

Despite their experience and fierce resistance, the Murakami fleet was defeated, and Nobunaga's ironclads played a pivotal role in breaking the Mōri forces. This defeat was a painful blow for the Murakami but also a testament to the changing nature of maritime warfare in Japan, where technology began to outweigh traditional tactics.

Relationships With Patrons: Cooperation and Betrayal

Although formally samurai, the Murakami operated as independent "people of the sea," which meant their loyalty to patrons like the Mōri, Ōtomo, and Kōno clans was often pragmatic (they could form alliances without being directly under their service). Their primary priority was maintaining control over the Seto Inland Sea and preserving their autonomy.

For example, between 1542 and 1582, the Murakami switched sides several times, alternately supporting the Ōtomo, Mōri, and Kōno clans, depending on political and economic benefits. Additionally, different branches of the Murakami clan sometimes fought against each other if their immediate interests dictated so. In 1582, the Noshima Murakami, under the patronage of the Mōri, defeated the Kurushima Murakami and took control of their islands, solidifying their position as the most powerful branch of the clan.

Powerful patrons needed the Murakami to achieve their maritime objectives, while the Murakami used these relationships to expand their influence and secure their domains. This complex game of loyalty and independence made them exceptional players who relied equally on strength and diplomacy.

The End of the Pirate Era: What Remained of the Kaizoku

Toyotomi Hideyoshi's Edict: The End of Pirate Autonomy

In 1588, as Toyotomi Hideyoshi moved toward the full unification of Japan, he issued the "Edict to Halt Piracy" (海賊停止令, kaizoku teishi-rei), aimed at suppressing independent maritime powers like the Murakami kaizoku. Aware of the strength of these autonomous pirates, Hideyoshi viewed them as potential threats to his authority. The edict required pirates to cease all independent activities and submit to central rule. Those who refused were forcibly removed from their island strongholds, and some were relocated inland.

This marked the dismantling of the key elements of Murakami power—their control over the Seto Inland Sea and their autonomous "maritime kingdom." However, the Murakami kaizoku did not disappear overnight; some of their structures were integrated into legitimate military and commercial fleets supporting the new centralized government. Others lost influence and gradually faded into obscurity.

Transformation and Decline

Although the Murakami clan ceased their piratical activities, they retained their maritime traditions. Some members of the clan were incorporated into regional military structures as coastal guards or maritime guides. For example, Murakami descendants participated in protecting Japanese diplomatic delegations, such as Korean missions from the Choseon state, which traveled through the Seto Inland Sea. However, some Murakami failed to survive these transitions, disappearing from the pages of history as they struggled against Toyotomi's centralized order.

The Legacy of Murakami in Culture and Traditions

Although their time of maritime dominance has passed, the legacy of the Murakami persists in various forms. Today, numerous traces of their power and influence can still be found.

On Innoshima Island, the traditional Horaku dance (奉楽舞, Horaku-mai), once performed by the Murakami to invoke blessings for victory at sea, is still celebrated. This ritual dance combines spirituality and the region’s maritime history.

The ruins of castles, such as those on Noshima and Innoshima, remain visible, serving as reminders of the Murakami’s strategic might. The Oyamazumi Shrine, to which the Murakami dedicated their poems, continues to be a pilgrimage site and a symbol of their cultural contributions.

Modern institutions like the Murakami Suigun Museum on Innoshima collect artifacts related to the pirates’ lives and activities, from weapons and armor to ship models. Visitors can explore their history in both military and cultural contexts.

On the Geiyo Islands, monuments commemorating the Murakami have been erected, such as sculptures of their leaders and fleets. One particularly popular figure is the statue of Tsuruhime, often called the "Joan of Arc of Japan," who fought alongside the Murakami.

Elements of the Murakami story appear in popular culture, such as the series One Piece, where pirates are depicted as charismatic heroes with exceptional abilities (though the series leans more toward southern pirates like the Wakō). There is also a film: Setouchi Kaizoku Monogatari. In games like Total War: Shogun 2, players can fight against or form alliances with the Murakami pirate faction.

Conclusion

The Murakami clan is one of the most fascinating chapters in Japan’s history—balancing samurai tradition with pragmatic and audacious piracy, warfare with literature. Their story is not just about domination over the waters of the Seto Inland Sea but also about how the art of administration and military tactics can coexist with culture and spirituality. In a time of turbulent change in Japan, the Murakami symbolized adaptation and survival, combining loyalty to patrons with the defense of their autonomy. Their world was full of paradoxes: pirates who also protected trade and warriors who composed poetry in moments of peace.

The Murakami legacy lives on in local traditions like the Horaku dance and in the memory of the places they once controlled. Their islands, shrines, and castle ruins serve as reminders of an era when this clan ruled the waters of Seto Naikai, and their name commanded respect among sailors and warriors.

The Murakami were not only lords of the seas but also individuals who understood that true power lies not just in military strength but in the ability to create order from chaos—through effective administration.

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"Strong Japanese Women"

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    未開    ソビエライ

 An enthusiast of Asian culture with a deep appreciation for the diverse philosophies of the world. By education, a psychologist and philologist specializing in Korean studies. At heart, a programmer (primarily for Android) and a passionate technology enthusiast, as well as a practitioner of Zen and mono no aware. In moments of tranquility, adheres to a disciplined lifestyle, firmly believing that perseverance, continuous personal growth, and dedication to one's passions are the wisest paths in life. Author of the book "Strong Women of Japan" (>>see more)

Personal motto:

"The most powerful force in the universe is compound interest." - Albert Einstein (probably)

  Mike Soray

   (aka Michał Sobieraj)

未開    ソビエライ

 An enthusiast of Asian culture with a deep appreciation for the diverse philosophies of the world. By education, a psychologist and philologist specializing in Korean studies. At heart, a programmer (primarily for Android) and a passionate technology enthusiast, as well as a practitioner of Zen and mono no aware. In moments of tranquility, adheres to a disciplined lifestyle, firmly believing that perseverance, continuous personal growth, and dedication to one's passions are the wisest paths in life. Author of the book "Strong Women of Japan" (>>see more)

Personal motto:

"The most powerful force in the universe is compound interest." - Albert Einstein (probably)

Mike Soray

(aka Michał Sobieraj)

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