A Thorough Explanation of the History and Remains of the Nanbu Jinya (Hokkaido) | Four Jinya Sites in Hakodate, Muroran, Oshamanbe, and Sawara
What is the Nanbu Jinya?
The Nanbu Jinya (Nanbu Fortifications) were military facilities built by the Nanbu Domain (present-day Morioka Domain, Iwate Prefecture) at the command of the shogunate during the late Edo period for the security and defense of Hokkaido (then known as Ezo). During the turbulent period of the late Edo period, multiple Jinya were established throughout Hokkaido to strengthen the defense system against the northward expansion of foreign powers, including Russia.
The Nanbu Jinya is not a single facility, but rather refers to a group of four Jinya: the original Jinya in Hakodate, and three branch Jinya in Muroran, Oshamanbe, and Sawara. These functioned as security bases for the Nanbu Domain in eastern Ezo and played a crucial role in the early modern history of Hokkaido.
Currently, the three former encampment sites in Muroran, Oshamanbe, and Sunahara are designated as national historic sites under the name “Eastern Ezo Nanbu Domain Encampment Sites,” and are preserved as valuable early modern castle remains within Hokkaido.
Historical Background of the Establishment of the Nanbu Encampment
Changes in the Situation Surrounding Ezo
From the late 18th to the 19th century, Russia’s southward expansion policy from the north intensified, making the defense of Japan’s northern border an urgent necessity. In 1792 (Kansei 4), Russian envoy Laxman arrived in Nemuro, and in 1804 (Bunka 1), Rezanov arrived in Nagasaki, increasing contact with Russia.
In response to this situation, the shogunate changed its policy of governing Ezo, which had previously been entrusted to the Matsumae Domain, and made Eastern Ezo a directly controlled territory in 1799 (Kansei 11). At this time, the shogunate ordered the Tsugaru and Nanbu domains to guard Ezo (Hokkaido), and the Nanbu domain was assigned to guard the area around Hakodate.
Establishment of the First Nanbu Jinya (1799-1821)
In 1799 (Kansei 11), the Nanbu domain established its first jinya (fortified residence) in Hakodate by order of the shogunate. This jinya was located at the top of Nanbu-zaka slope at the foot of Mount Hakodate (near the current parking lot for the Hakodateyama Ropeway base station). The name Nanbu-zaka originates from the fact that this jinya was located on a slope.
The initial jinya site was approximately 16,200 square meters, but it was later expanded by approximately 19,800 square meters, reaching a size of over 36,000 square meters. Nanbu domain samurai were permanently stationed at this jinya, responsible for guarding Hakodate Port and monitoring the surrounding waters.
However, with the shogunate’s return of Ezo (Hokkaido) to the Matsumae Domain in 1821 (Bunsei 4), the Nanbu Domain’s security duties were relieved, and the First Nanbu Jinya (fortified residence) was abolished.
Establishment of the Second Nanbu Jinya (1855-1868)
Following Commodore Perry’s arrival in 1853 (Kaei 6), international tensions around Japan intensified further. Even after the signing of the Treaty of Friendship between Japan and Russia in 1854 (Ansei 1), vigilance against Russia’s northward expansion continued, and the shogunate decided to strengthen security in Ezo again.
In April 1855 (Ansei 2), the shogunate ordered the five domains of Sendai, Akita, Nanbu, Tsugaru, and Matsumae to share the responsibility of guarding Ezo. The Nanbu Domain primarily guarded Hakodate’s Omote-desaki (a cape), and its security area extended along a vast coastline from Cape Esan to Horobetsu in eastern Ezo (present-day Horobetsu, Noboribetsu City).
In this second security system, the Nanbu Domain established its main encampment north of Yachigashira in Hakodate. To accommodate the vastness of the security area, in 1856 (Ansei 3), it built three branch encampments in Muroran, Oshamanbe, and Sawara.
This system continued until the Boshin War in 1868 (Meiji 1). However, when the Boshin War spread to the Oshu region, the Nanbu Domain, which sided with the former shogunate, burned down its encampments and withdrew to Morioka.
Details of the Hakodate Moto-Jinya (Former Encampment)
Location and Geographical Characteristics
The Hakodate Moto-Jinya was located in Motomachi, Hakodate City, Hokkaido. Specifically, it was located on Nanbu-zaka Hill at the foot of Mount Hakodate, and the site is believed to be around the current parking lot for the base station of the Hakodateyama Ropeway.
Its location at the foot of Mount Hakodate was a strategic point overlooking Hakodate Port, making it ideal for monitoring and defending the harbor. It can be said that the layout combined the functions of defense against attacks from the sea and monitoring the comings and goings in and out of the port.
Scale and Structure of the Jinya (Fortified Residence)
The initial site of the first Jinya was approximately 16,200 square meters, but it was later expanded to over 36,000 square meters. This is equivalent to about three-quarters of the size of the Tokyo Dome.
It is believed that the Jinya contained barracks for samurai, an armory, food storage, and training grounds. In the second Jinya (after 1855), the main Jinya was located north of Yachigashira, and a more organized security system was established.
Current Situation
The former Hakodate Jinya (fortified residence) site is now a residential area and ropeway-related facilities, with very few remains of the Jinya left. However, the place name Nanbu-zaka (Southern Slope) still remains, conveying the history of the Nanbu Jinya’s existence in this area.
Although many tourists visit the area around Mount Hakodate, few are aware of the existence of the Nanbu Jinya, making it a hidden historical heritage of the region.
Mororan Jinya Site (Muroran City)
History of the Jinya’s Establishment
In 1856 (Ansei 3), the Nanbu Domain established the Mororan Jinya in what is now Jinya-cho, Muroran City, as an outpost of the Hakodate Jinya. Muroran is a natural harbor facing the Pacific Ocean and was an important base for coastal defense in eastern Ezo (Hokkaido).
Because the Nanbu Domain’s security area extended over a wide area from Cape Esan to Horobetsu, a permanent base was needed in areas far from Hakodate. The Mororan Jinya functioned as the core of this eastern defense.
Structure and Scale of the Jinya (Fortified Residence)
The Mororan Jinya had a distinctive structure: a square double earthen rampart. This defensive structure, with double earthen ramparts surrounding both the inner and outer walls, is a valuable relic demonstrating late Edo period castle construction technology.
Approximately 100 Nanbu samurai were permanently stationed at the Jinya. This was a considerably large personnel deployment for an outpost, indicating the strategic importance of the area.
Within the Jinya, there were residences for the samurai, an armory, a training ground, and a battery guardhouse. The battery guardhouse was a facility for managing the coastal artillery batteries, serving as the front line for directly responding to threats from the sea.
Value as a National Historic Site
The Mororan Jinya site was designated a National Historic Site on May 1, 1934 (Showa 9), as part of the “Nanbu Domain Jinya Site in Eastern Ezo.” It is the only National Historic Site in Muroran City and one of the most important historical sites in Hokkaido as a late Edo period castle site.
A portion of the earthworks is well-preserved, making it a valuable resource for understanding the structure of a jinya (fortified residence) from the late Edo period. The structure, a double-layered square earthwork, demonstrates the latest defensive technology of the time, influenced by Western fortification techniques.
Access and Visiting Information
The Mororan Jinya Site is located in Jinya-cho, Muroran City, and is accessible by car in about 10 minutes from Higashi-Muroran Station on the JR Muroran Main Line, or by bus. It has been developed as a historical park, where visitors can view the remains of the earthworks and explanatory signs.
The surrounding area retains the place name Jinya-cho, allowing visitors to feel the historical atmosphere. From spring to autumn, it serves as a lush green park and a place of relaxation for citizens.
Oshamanbe Jinya Site (Oshamanbe Town)
Establishment and Role of the Jinya
The Oshamanbe Jinya was an outpost of the Nanbu Domain, established in 1856 (Ansei 3) in what is now Oshamanbe Town. Oshamanbe, facing Uchiura Bay (Funka Bay), was a strategically important transportation hub located midway between Hakodate and Muroran.
Located in the central part of the Nanbu Domain’s security area, this encampment also functioned as a communication hub connecting the Hakodate main encampment and the Muroran encampment. It played a dual role: monitoring the coastline and securing communication routes to the inland areas.
Scale of the Encampment and Garrison Forces
Nanbu Domain samurai were permanently stationed at the Oshamanbe encampment, responsible for coastal security and monitoring the surrounding area. While not as large a garrison as the Muroran encampment, it functioned as an important base for regional defense.
The structure of the encampment, like other outpost encampments, was a rectangular facility surrounded by earthen ramparts and a moat. It is believed that barracks, armories, and food storage facilities were located inside.
Preservation Status as a National Historic Site
The Oshamanbe encampment site is designated as a national historic site as part of the “Nanbu Domain Encampment Sites in Eastern Ezo.” On May 23, 1975 (Showa 50), Oshamanbe Town was designated as the managing body.
Currently, some of the remains are preserved, and an explanatory sign has been installed. While not as prominent as the remains of the Mororan Jinya site, it is protected as a valuable historical site that conveys the history of the region.
Access Information
The Oshamanbe Jinya site is located in the town center of Oshamanbe, within walking distance of Oshamanbe Station on the JR Hakodate Main Line. It is located along National Route 5, making it easily accessible by car.
Sunahara Jinya Site (Mori Town)
Background of the Jinya’s Establishment
The Sunahara Jinya was a branch office (sub-official post) of the Nanbu Domain, located in the Sunahara area of present-day Mori Town, Kayabe District, Hokkaido. Sunahara is located on the eastern shore of Uchiura Bay, in the area spreading at the southern foot of Mount Komagatake.
In 1856 (Ansei 3), a branch station was established in Shikenmachi, Sunahara, with approximately 50 soldiers stationed there. This encampment functioned as a base to protect the western edge of the Nanbu Domain’s security area.
Characteristics of the Encampment
Compared to other branch encampments, the Sunahara encampment was smaller in scale, but it was an important surveillance point along the Uchiura Bay coast. Due to its geographical location at the foot of the active volcano, Mount Komagatake, it faced the challenging task of responding to natural disasters.
The force of approximately 50 soldiers was a standard size for a branch station, and it housed the personnel necessary for daily coastal security and emergency response.
Current Status as a Historic Site
The Sunahara encampment site is designated as a national historic site as the “Nanbu Domain Encampment Site of Eastern Ezo.” Mori Town is the managing body and is working to preserve the historic site.
While no buildings of the encampment remain in the current Sunahara area, explanatory signs and other markers have been installed, preserving it as a local historical heritage site. The history of the Nanbu clan’s samurai being stationed here is still passed down among the local residents.
Visiting Information
The Sunahara Jinya Ruins are located in the Sunahara district of Mori Town, and the nearest station is Oshima-Sunahara Station on the JR Hakodate Main Line. It is located along National Route 278, making it easily accessible by car.
Military Characteristics and Defensive System of the Nanbu Jinya
Structure of the Square Double Earthen Embankment
The square double earthen embankment, particularly prominent at the Nanbu clan’s outposts, especially the Mororan Jinya, demonstrates the characteristics of castle construction technology during the late Edo period. The double embankment is based on the concept of multi-layered defense, where even if the outer embankment is breached, the inner embankment can continue the defense.
A moat was constructed between the embankments, making it difficult for attackers to enter. This was an advanced defensive system for its time, influenced by Western-style bastion fortification techniques.
Coordination with the Forts
The encampment had an attached fort guard station, establishing a defensive system in coordination with the forts (daiba) located along the coast. Cannons were positioned at the forts, responsible for fire defense against attacks from the sea.
The encampment functioned as a rear support base for the forts, fulfilling roles such as ammunition resupply, rest for gunners, and standby for reserve forces. This encampment-fort system was the standard form of coastal defense during the late Edo period.
Security System and Daily Duties
The Nanbu samurai stationed at each encampment took turns performing duties such as coastal surveillance, fort security, and patrols. The level of alert was raised, especially during periods when the arrival of foreign ships was expected.
Daily training included martial arts training, cannon operation training, and emergency response training. Building relationships with local residents, gathering information, and maintaining facilities were also important duties.
Life of Nanbu Clan Samurai in Ezo (Hokkaido)
Realities of Garrison Life
Nanbu clan samurai endured a harsh garrison life in Ezo, far from their home province of Morioka. The winter cold, in particular, was even more severe than in Morioka, making heating and food supplies major challenges.
Samurai were dispatched to Ezo on a rotating basis, typically serving for several months to a year. Many were sent alone without their families, and life away from home was mentally and physically demanding.
Supply of Food and Supplies
While some food and supplies necessary for life at the encampment were procured locally, much was transported by sea from Morioka or Hakodate in their home province. Especially in winter, rough seas made supplying supplies difficult, so sufficient stockpiling was essential.
Rice, miso, salt, and dried foods were the main food sources. While they sometimes procured fresh ingredients from local fisheries and agriculture, their lifestyle was simple due to their limited budget.
Interaction with Local Residents
The Nanbu samurai also interacted with the local Ainu people and Japanese residents. Obtaining local information was crucial for carrying out their security duties, and good relationships with the residents were essential.
On the other hand, the presence of an armed military organization also brought tension to the local community. It is believed that various frictions existed between the samurai and the local residents, including cultural differences and economic interests.
The Boshin War and the End of the Nanbu Camp
Participation in the Ouetsu Reppan Alliance
In 1868 (Meiji 1), when the Boshin War broke out, the Nanbu domain joined the Ouetsu Reppan Alliance and fought against the new government forces on the side of the former shogunate. This decision drastically changed the fate of the Nanbu samurai stationed in Ezo (Hokkaido).
As the Boshin War spread to the Oshu region, the Nanbu Domain decided to withdraw its samurai from its various encampments in Ezo (Hokkaido) in order to defend its homeland.
Burning of Encampments and Withdrawal
In 1868, the Nanbu Domain burned down all of its encampments—Hakodate Moto-Jinya, Mororan Jinya, Oshamanbe Jinya, and Sunahara Jinya—and withdrew to Morioka. This was a measure to prevent the encampments from being used by the new government forces or hostile forces.
At Mororan Jinya, the samurai themselves set fire to the encampment they had built and withdrew with their weapons and supplies. The encampment, which had functioned as a security base in eastern Ezo for approximately 10 years, was thus reduced to ashes.
The Nanbu Domain After the Meiji Restoration
After the Boshin War, the Nanbu Domain surrendered to the new government, and the lord was placed under house arrest. However, the Nanbu Domain was not completely abolished, but continued to exist as the Morioka Domain, later becoming Morioka Prefecture and then Iwate Prefecture.
Ezochi (Hokkaido) became a direct territory of the Meiji government, and the Hokkaido Development Commission was established, marking the beginning of full-scale development. The sites of the Nanbu Jinya (fortified residences) were either sold off to private individuals or used as public land in this new era.
Cultural Value of the Nanbu Jinya Sites
Significance as a National Historic Site
The “Nanbu Domain Jinya Sites in Eastern Ezochi” (Mororan Jinya Site, Oshamanbe Jinya Site, and Sunahara Jinya Site) were designated a National Historic Site on May 1, 1934 (Showa 9). This indicates that they are extremely important cultural assets as early modern castle remains in Hokkaido.
There are few remains nationwide that specifically show the northern defense system during the late Edo period, making the Nanbu Jinya Sites valuable historical materials for understanding the international situation and Japan’s response at the time.
Position in the History of Early Modern Japanese Castles
The Nanbu Jinya (Nanbu Fortified Residence) occupies an important position in the history of Japanese castles as a transitional castle that fused traditional Japanese castle construction techniques with Western-style fortifications. Its structure, a double-layered square earthen rampart, shows a unique development adapted to Japanese terrain and tactics while being influenced by bastion-style fortifications.
Furthermore, while the Jinya form was established throughout Japan as an outpost of daimyo (feudal lords) during the Edo period, Jinya in Hokkaido had a particularly strong military character, with their defensive function being emphasized.
Significance in the History of Hokkaido
The Nanbu Jinya is an important historical site that shows the process by which Hokkaido was fully integrated into the Japanese system of governance. During the Edo period, Ezo (Hokkaido), while under the rule of the Matsumae Domain, had formed a unique society distinct from that of Honshu.
The security system established by various domains during the late Edo period represents a crucial turning point in the history of Hokkaido, preceding the full-scale development by the Hokkaido Development Commission after the Meiji Restoration. The Nanbu Jinya can be considered a symbolic relic of this period.
Preservation and Utilization of the Nanbu Jinya Sites in Modern Times
Status of Historical Site Preservation
Currently, the Mororan Jinya site is managed by Muroran City, the Oshamanbe Jinya site and its surroundings by Oshamanbe Town, and the Sunahara Jinya site by Mori Town.
At the Mororan Jinya site, a portion of the earthworks is well-preserved, and it has been developed as a historical site park. Information boards and guides have been installed to allow visitors to learn about the history.
At the Oshamanbe Jinya site and the Sunahara Jinya site, although very few building remains remain, they have been designated as historical sites and are protected from development.
Utilization as Educational and Tourism Resources
Each Jinya site is used as teaching material for local history education. Local elementary and junior high schools conduct activities to learn about the history of the Nanbu Jinya as part of their local history studies, including visits to the historical sites.
As a tourist resource, it has become a place visited by tourists interested in history and castle enthusiasts. In particular, the Mororan Jinya Ruins are introduced as one of Muroran City’s historical tourist attractions.
Future Challenges and Prospects
There are several challenges in preserving and utilizing the Nanbu Jinya Ruins. Firstly, continuous preservation management is necessary to prevent weathering and deterioration of the remains. Earthen structures, especially earthworks, are particularly susceptible to erosion from rainwater and the effects of vegetation, requiring regular maintenance.
Secondly, disseminating information to let more people know about the historical value of the Nanbu Jinya is crucial. New methods of historical transmission are expected, such as the creation of reconstructed CG using digital technology and experiential exhibitions using VR/AR.
Thirdly, regarding the former Jinya Ruins in Hakodate, since very few remains exist, efforts are needed to convey history, such as the installation of monuments and the improvement of explanatory signs.
Nanbu Jinya and Other Ezo Guard Facilities
Comparison with Jinya of Other Domains
By order of the shogunate in 1855, in addition to the Nanbu Domain, the Sendai, Akita, Tsugaru, and Matsumae Domains were also responsible for guarding Ezo (Hokkaido). Each domain established jinya (fortified residences) and fortifications in their respective areas of responsibility.
The Sendai Domain established its main jinya in Shiraoi (present-day Shiraoi Town) and set up several branch jinya. The Tsugaru Domain was responsible for the Soya (present-day Wakkanai City) area, and the Akita Domain dispatched troops from the Noshiro area.
While each of these jinya had its own unique structure and scale, they all shared the characteristic of being defensive facilities surrounded by square earthen ramparts and moats. The Nanbu Jinya’s square double earthen rampart was a structure that particularly emphasized defensiveness.
The Role of the Matsumae Domain
The Matsumae Domain played a central role in governing Ezo (present-day Hokkaido) throughout the Edo period, but temporarily lost its authority when Ezo came under direct control by the shogunate in 1799. Even after regaining its territory in 1821, it was again incorporated into the shogunate’s Ezo security system in 1855.
The Matsumae Domain possessed extensive experience in governing Ezo and was well-versed in trade and diplomacy with the Ainu people. Its knowledge and experience were also utilized in the security of other domains’ encampments.
Relationship with the Hakodate Magistrate’s Office
In 1854, the shogunate established the Hakodate Magistrate’s Office, making it the central institution for governing Ezo. The Hakodate Magistrate’s Office oversaw the encampments of each domain and formulated and implemented overall security plans.
The encampments of each domain, including the Nanbu Domain, operated under the command of the Hakodate Magistrate’s Office and regularly reported on their security status. In emergencies, instructions were transmitted from the magistrate’s office to each encampment, and coordinated responses were taken.
Place Names and Legends Left Behind by the Nanbu Encampment
Nanbu-zaka (Hakodate City)
Nanbu-zaka in Hakodate City is a slope located at the foot of Mount Hakodate. Its name originates from the fact that the Nanbu Encampment was established on this slope. It remains one of Hakodate’s representative slopes and attracts many tourists.
From Nanbu-zaka, one can enjoy a panoramic view of Hakodate Port and the city, allowing one to imagine the Nanbu samurai monitoring the sea from this location.
Jinya-cho (Muroran City)
Jinya-cho in Muroran City is a place name derived from the establishment of the Mororan Encampment. It remains a town name today and is part of the local identity.
Jinya-cho has a historical park, which serves as a place of relaxation for local residents. Neighborhood associations also engage in activities to pass on the history of the Nanbu Encampment.
Local Legends
Various legends about the Nanbu samurai remain in the areas where each encampment was established. Stories of the samurai’s interactions with local residents, their experiences enduring harsh winters, and the waka poems they composed longing for their hometowns—heartwarming anecdotes are passed down through generations.
Furthermore, stories of the samurai bidding farewell to local residents upon their departure from the encampments, and tales of mourning for samurai who died in the Boshin War are also recounted, conveying the weight of history.
Summary: Historical Significance of Nanbu Encampments
The Nanbu encampments were military facilities established throughout Hokkaido to respond to the international crises faced by Japan during the late Edo period. Centered around the Hakodate Moto-Jinya (original encampment), three branch encampments were built in Mororan, Oshamanbe, and Sunahara, and they were responsible for guarding eastern Ezo (Hokkaido) for approximately 10 years.
These encampments hold significant historical importance not only as military facilities, but also as a precursor to the development of Hokkaido and as part of Japan’s northern policy during its modernization process.
These encampments hold important historical significance. Currently, the three former encampment sites of Mororan, Oshamanbe, and Sunahara are preserved as national historical sites, representing valuable cultural heritage of Hokkaido. Visiting these sites allows one to reflect on the lives of the Nanbu samurai who fulfilled their duties in the northern land during the turbulent Bakumatsu period.
The history of the Nanbu encampments is a story that should be passed down as a source of regional pride, and it is an indispensable historical legacy for understanding Japan’s transition from the early modern to the modern era.
