Complete Guide to Shōzui Castle: The History and Highlights of the Fiery Provincial Headquarters of Medieval Awa Province
What is Shōzui Castle?: A Medieval Castle Renowned as “Shōzui of the Realm”
Shōzui Castle is a medieval castle located in Shōzui, Aizumi-cho, Itano-gun, Tokushima Prefecture. From the Kamakura period to the Azuchi-Momoyama period, it was renowned as “Shōzui of the Realm” as the political, economic, and cultural center of Awaji, Sanuki, and Awa provinces, and is known as an extremely important castle site in the history of medieval Japan.
Currently, the Shōzui Castle Ruins are designated as a National Historic Site, and on April 6, 2017 (Heisei 29), it was selected as one of the Continued Top 100 Japanese Castles (No. 175). It is a rare flatland castle among the medieval castles remaining in Tokushima Prefecture, and consists of two areas: the “Shōzui Residence Ruins,” which was the residence, and the “Shōzui Castle Ruins,” which was a military base.
As a medieval regional city, the castle town flourished to an unprecedented degree, serving as the base of operations for approximately 240 years under the nine generations of the Hosokawa valuable clan and three generations of the Miyoshi clan, playing a significant role in history. Continued archaeological excavations are still being conducted, making it a site for understanding the realities of a medieval provincial governor’s residence.
History of Katsuzui Castle: From the Kamakura Period to its Fall in the Tensho Era
Kamakura and Nanboku-cho Periods: Establishment of the Provincial Governor’s Residence by the Hosokawa Clan
Katsuzui first appears on the historical stage during the late Kamakura period and the Nanboku-cho period. The Hosokawa clan, appointed as the governor of Awa Province, established initially their residence in Akizuki, Awa City, but later moved it to Katsuzui, a strategically important location with economic advantages.
Katsuzui is located near the mouth of the Yoshino River, offering convenient water transport. Furthermore, it was a junction for land routes to various parts of Awa Province, providing ideal conditions for establishing a provincial governor’s residence. The Hosokawa clan also referred to this area as “Awa Yakata” and “Katsuzui Yakata,” and used it as their base for controlling Awa Province.
Muromachi Period: The Era of Prosperity under the Hosokawa Clan
Throughout the Muromachi period, Katsuzui flourished as the political, economic, and cultural center of Awa Province. As a powerful shugo daimyo (provincial governor) under the Muromachi shogunate, the Hosokawa clan extended their influence not only to Awa Province but also to Sanuki and Awaji Provinces, becoming the most powerful force in Shikoku.
During this period, Katsuzui not only functioned as a shugo residence but also developed a strong character as a commercial city. Archaeological excavations have unearthed numerous artifacts demonstrating the cutting edge of culture at the time, including Chinese ceramics, tea ceremony utensils, and high-quality lacquerware, confirming that Katsuzui was culturally advanced.
Under the Hosokawa clan, Katsuzui was also called “Shimo Yakata” (lower yakata), and while maintaining close ties with the main Hosokawa family in Kyoto, it functioned as a political and cultural center in Shikoku.
Sengoku Period: The Rise and Fiery Age of the Miyoshi Clan
With the start of the Sengoku period, the Miyoshi clan, vassals of the Hosokawa clan, captured real power. From the time of Miyoshi Motonaga, father of Miyoshi Nagayoshi, the Miyoshi clan established their base in Shōzui and became the de facto rulers of Awa Province, replacing the Hosokawa clan.
Miyoshi Nagayoshi expanded his influence into the Kinai region and, at one point, wielded such power that he was called a “ruler of Japan,” but his true base remained Shōzui in Awa. During the reigns of three generations of the Miyoshi clan (Motonaga, Nagayoshi, and Nagaharu), Shōzui reached its peak, and the castle town flourished greatly.
Archaeological excavations have uncovered large building remains and the remains of a dry landscape garden at the site of the Shōzui residence from this period, giving a glimpse into the grandeur of a Sengoku daimyo’s residence. Furthermore, numerous townhouse remains and road remains have been discovered in the castle town, revealing the existence of a naturally developed urban space.
Tensho 10 (1582): Fall of Katsuzui Castle to the Chosokabe Clan
The history of Katsuzui Castle reached a major turning point in Tensho 10 (1582). Chosokabe Motochika, a Sengoku daimyo of Tosa Province, invaded Awa Province with the aim of unifying Shikoku and captured Katsuzui Castle.
Miyoshi Nagaharu, the last head of the Miyoshi clan, had already lost real power and become weakened. Under a fierce attack by the Chosokabe forces, Katsuzui Castle fell and was burned down. This battle marked the end of Katsuzui’s approximately 240-year reign as the center of Awa Province.
Subsequently, with Toyotomi Hideyoshi’s conquest of Shikoku, the Chosokabe clan surrendered, and Awa Province came under the control of the Hachisuka clan. The Hachisuka clan built Tokushima Castle as their new base, and Katsuzui completely lost its position as a political center.
Structure and Characteristics of the Katsuzui Castle Ruins
Katsuzui Castle Ruins (within the grounds of Kenshoji Temple)
The Katsuzui Castle ruins are located within the grounds of the present-day Kenshoji Temple. Kenshoji Temple is the family temple of the Miyoshi clan, and the temple grounds contain the graves of four generations of the Miyoshi clan and a monument to Katsuzui Yoshiie.
Parts of the moat and earthworks remain at the castle ruins, preserving the appearance of a medieval castle. While archaeological excavations have been limited, it has been confirmed that the castle functioned as a military base. Katsuzui Castle was a flatland castle, primarily composed of defensive structures consisting of moats and earthworks.
No elements of early modern castles, such as stone walls, are found, maintaining the typical form of a medieval flatland castle. The castle was relatively small in scale and is thought to have primarily functioned as a military base during emergencies.
Katsuzui-kan Site: Residence of a Shugo (Provincial Governor) and Sengoku Daimyo (Warring States Period Daimyo)
The Katsuzui-kan site is located south of the Katsuzui Castle ruins, across Prefectural Road 14. It was the residence and administrative center of the Shugo and Sengoku Daimyo. Currently, it is maintained as a historical park and open to the public.
Excavation surveys, which began in 1994, have uncovered the following important remains:
Building Foundation Stones: Numerous foundation stones of large buildings have been discovered, revealing the layout of buildings such as the main hall and meeting hall. The scale and layout of the buildings confirm that it was a high-ranking Shugo residence and Sengoku Daimyo residence.
Dry Landscape Garden: The remains of a dry landscape garden in the style of the Muromachi period were discovered in excellent condition. The garden shows strong cultural influence from Kyoto, indicating that Katsuzui, despite being a regional city, actively incorporated central culture. Currently, this garden has been restored and maintained, allowing visitors to imagine its former appearance.
Moat Remains: The remains of a moat surrounding the residence have been confirmed, serving both a defensive function and an indicator of the residence’s status. Numerous artifacts have been unearthed from the moat, providing clues to the life and culture of the time.
Road Remains: A systematically developed road network has been discovered around the residence. This is important evidence that Katsuzui was not merely a castle but possessed urban functions.
Katsuzui Guardian Town Site: The Reality of a Medieval City
A vast castle town formed around the Katsuzui Castle site. The remains of this castle town, along with the castle site, are designated as a National Historic Site under the name “Katsuzui Guardian Town Site.”
Excavation surveys have uncovered numerous building remains, wells, roads, and ditches, revealing a level of prosperity unusual for a medieval regional city. A wealth of artifacts have been unearthed, including Chinese celadon and white porcelain, domestic pottery, wooden objects, and metal objects, among others.
Of particular note is the high probability that Katsuzui was also a center for the production and distribution of indigo, a specialty product of Awa Province. The place name Aizumi-cho itself indicates that it was an indigo-producing area, and it is presumed that indigo played a significant role in Katsuzui’s economic prosperity.
Archaeological Findings and Excavated Artifacts
Ongoing Archaeological Excavations
Excavations have been continuously conducted at the Katsuzui Castle Site since 1994, with new discoveries made every year. The scale and state of preservation of the excavated artifacts and discovered structures are exceptionally good compared to other sites nationwide, providing first-class materials for understanding the reality of a medieval provincial governor’s residence and a Sengoku period daimyo’s residence.
These achievements were recognized, and the site was designated a National Historic Site on January 29, 2001. Research and investigations continue, primarily led by the Aizumi Town Board of Education, and new knowledge is being accumulated one after another.
Major Excavated Artifacts
The following important artifacts have been unearthed during the excavation:
Ceramics: Numerous high-quality ceramics, including celadon, white porcelain, and blue-and-white porcelain, were found, likely imported through overseas trade, indicating that Shōzui was integrated into a wide-area trading network.
Tea Ceremony Utensils: Tea ceremony utensils such as tea bowls, tea caddies, and flower vases have also been discovered, indicating that tea ceremony culture flourished in Shōzui. These artifacts attest to the high level of cultural sophistication of the Sengoku period daimyo (feudal lords).
Wooden Artifacts: Organic artifacts such as lacquerware, clogs, and bentwood boxes have also been found in good condition. Some of the lacquerware, in particular, are decorated with advanced techniques, revealing the level of craftsmanship at the time.
Metal Artifacts: In addition to weapons such as swords and arrowheads, copper coins and decorative metal fittings have also been unearthed.
Roof Tiles: Numerous roof tiles used in buildings have been unearthed, confirming the existence of tiled buildings.
These artifacts are on display at the Katsuzui Castle Site Exhibition Room and the Aizumi Town History Museum “Ai no Yakata,” and are open to the public.
Current Katsuzui Castle Site: Developed as a Historical Park
Katsuzui Castle Site Historical Park
The Katsuzui Castle Site has been developed as a historical park and is open to the public. The park features a restored dry landscape garden, building foundation stones, and moat remains, allowing visitors to experience the atmosphere of a medieval provincial governor’s residence and a Sengoku period daimyo’s mansion.
The vast grounds are covered in lawns, making it a pleasant environment for strolling. Information boards are also installed, allowing visitors to read explanations of the historical background and remains while exploring.
Katsuzui Castle Site (Kenshoji Temple)
The Katsuzui Castle Site is now part of the grounds of Kenshoji Temple, the family temple of the Miyoshi clan. As it is located within temple grounds, consideration is necessary when visiting, but you can see historically important sites such as the tombs of the four generations of the Miyoshi clan and the monument to Yoshiie Katsuzui.
Parts of the moat and earthworks remain, making it a valuable place to see the remains of a medieval castle.
Continued Top 100 Japanese Castles Stamp
Katsuzui Castle was selected as one of the Continued Top 100 Japanese Castles (number 175) in 2017. Stamps can be obtained at the Katsuzui excavation site office and the Aizumi Town History Museum “Ai no Yakata”. It is a must-see historical site for castle enthusiasts.
Castle Seal
Katsuzui Castle sells a castle seal planned by the local “Katsuzui Castle Future Connection Team”. Dyed in indigo using Aizumi town’s specialty indigo, the castle seal is a popular item unique to this region.
The “Katsuzui Castle Future Connection Team” continues its activities to promote the charm of Katsuzui Castle, including holding the “Aizumi Smiley Marche” at the Katsuzui Castle ruins.
Access and Usage Guide to Katsuzui Castle Ruins
Access by Public Transportation
If using JR:
- Get off at JR Kotoku Line “Katsuzui Station,” approximately 15 minutes on foot.
- Exit the station, cross the railway crossing, and head west to reach the Katsuzui Castle ruins.
Katsuzui Station is approximately 10 minutes from Tokushima Station on the Kotoku Line, making access relatively convenient.
Access by Car
Using the Expressway:
- Approximately 5 minutes from the Aizumi IC on the Tokushima Expressway
- Convenient access by car as parking is available.
Using General Roads:
- Accessible from National Route 11, Prefectural Route 14, etc.
- Approximately 20 minutes by car from the center of Tokushima City
Facility Information
Katsuzuikan Ruins Historical Park:
- Location: Katsuzui, Aizumi-cho, Itano-gun, Tokushima Prefecture
- Opening Hours: Always open
-Admission Fee: Free
- Parking: Available (Free)
Katsuzui Excavation Site Office:
- Opening Hours: Weekdays 9:00-16:00 (Closed on Saturdays, Sundays, and public holidays)
- Exhibits: Results of the excavation survey, some of the excavated artifacts
-Admission Fee: Free
Aizumi Town History Museum “Ai no Yakata”:
- Opening Hours: 9:00-17:00
- Closed: Tuesdays (or the following day if Tuesday is a public holiday), New Year holidays
- Admission Fee: Adults 300 yen, Junior and Senior High School Students 200 yen, Elementary School Students 150 yen
- Exhibits: Artifacts excavated from the Katsuzui Castle Ruins, history of indigo dyeing, etc.
Points to Note When visiting the Katsuzui Castle Ruins, keeping the following points in mind will make your visit more fulfilling:
- Katsuzui Castle Ruins Historical Park: First, visit the historic park to see the reconstructed garden and the remains display to get an overview.
- Katsuzui Castle Ruins (Kenshoji Temple): Cross the prefectural road and visit the castle ruins within the grounds of Kenshoji Temple on the north side.
- Exhibition Facilities: See excavated artifacts and detailed explanations at the excavation site office and the Indigo Museum.
- Exploring the Surrounding Area: If you have time, it is recommended to walk around the area of the Katsuzui Ruins in Shugo-cho.
Historical Significance and Future Prospects of Katsuzui Castle
Importance in Medieval History Research
The Katsuzui Castle Ruins are an extremely important archaeological site for understanding the realities of local governance in Japanese medieval history, particularly during the Muromachi and Sengoku periods. It is one of the few examples where the transition from a provincial governor’s residence to a Sengoku daimyo’s residence can be empirically studied, making its academic value immeasurable.
In particular, it provides valuable information on many research themes, including the process of power transfer from the Hosokawa clan to the Miyoshi clan, the structure of medieval cities, and the acceptance and development of culture in the provinces.
Utilization as a Regional Resource
In Aizumi Town, the Katsuzui Castle Ruins are positioned as an important cultural resource of the region, and various utilization projects are being implemented. The town is working in collaboration with local residents to preserve and utilize the historical site through the development of a historical park, the enhancement of exhibition facilities, and the holding of events.
The activities of citizen groups such as the “Katsuzui Castle Future Connection Team” are also active, serving as a model case for community-based utilization of historical sites.
Future Research and Development Plans
Continued archaeological excavations are planned at the Katsuzui Castle site, and new discoveries are expected. In particular, many aspects remain unclear, such as the overall structure of the town castle and its relationship to indigo production.
Aizumi Town plans to formulate a historical site development plan based on the results of the research and proceed with development in stages. In the future, the aim is to create a historical park where visitors can more concretely experience the appearance of the medieval city of Katsuzui.
Summary: The Charm of Katsuzui Castle, the Center of Medieval Awa
Katsuzui Castle was the most important base in medieval Shikoku, serving as a base for powerful daimyo such as the Hosokawa and Miyoshi clans for approximately 240 years. Not only was it a political center, but it also boasted a high level of economic and cultural development, prospering to the point of being called “Katsuzui of the Realm.”
Although it disappeared from the historical stage after its fall in 1582, the abundant remains and artifacts still lying beneath the ground eloquently tell the story of a provincial city in medieval Japan. Designated a National Historic Site and one of the Continued Top 100 Japanese Castles, the Katsuzui Castle Ruins are a must-see for history buffs and anyone interested in medieval history.
When visiting Tokushima Prefecture, be sure to visit the Katsuzui Castle Ruins and experience the remnants of this medieval city that once flourished as the political, economic, and cultural center of Shikoku. With ongoing archaeological excavations, further discoveries are expected at Katsuzui Castle, making it a site to keep an eye on.
