Yamazaki Castle (Chiba Prefecture) Complete Guide | History and Highlights of the Two Castle Ruins in Katori City and Noda City
There are two castle ruins in Chiba Prefecture named “Yamazaki Castle.” One is a medieval castle associated with the Iizasa clan, located in Choji, Katori City. The other is a modern castle built by Okabe Nagamori, located in Yamazaki, Noda City. This article provides a detailed explanation of these two Yamazaki Castles, including their historical background, existing remains, highlights, and access methods.
What are the Yamazaki Castles in Chiba Prefecture?
The two Yamazaki Castles in Chiba Prefecture are separate castles built at different times and by different lords. Although they share the same name and are often confused, each has its own unique history and characteristics.
Yamazaki Castle in Katori City
Yamazaki Castle, located in Choji, Katori City, is a flatland castle built in the medieval period. Currently, the Sobako Shrine stands on the site, and castle ruins remain within the shrine grounds and surrounding area.
Yamazaki Castle in Noda City
Yamazaki Castle, located in Yamazaki, Noda City, was built in 1590 by Okabe Nagamori, a retainer of Tokugawa Ieyasu. Currently, Kaifuku-ji Temple stands on the site, and no clear remains of the castle have been found.
History of Yamazaki Castle (Katori City)
Construction and Lord
Regarding the detailed construction date and lord of Yamazaki Castle in Katori City, there are many unknowns due to a lack of reliable historical records. However, based on the castle’s location and the surrounding historical context, it is presumed to have been a castle related to the Iizasa clan.
The Iizasa clan was a samurai family based in Shimosa Province, and Iizasa Nagaisai Ienori, in particular, was a swordsman known as the founder of the Tenshin Shoden Katori Shinto-ryu school. Because they held power in an area close to Katori Shrine, it is highly likely that Yamazaki Castle was also within the Iizasa clan’s sphere of influence.
Yamazaki Castle in the Sengoku Period
During the Sengoku period, Shimosa Province was a complex area of power centered around the Chiba clan. The Katori region was strategically important, possessing the Katori Shrine, a vital religious institution, and also a key point for water transport on the Tone River system.
Yamazaki Castle is thought to have functioned as a base for the local lord within this regional context. Its relatively small size and near-single-enclosure structure suggest it likely served more as an emergency refuge or watchtower than as a center of regional control.
Date of Abandonment
There are no clear records of when Yamazaki Castle was abandoned. It is likely that it was abandoned during the process of consolidating small medieval castles following Toyotomi Hideyoshi’s siege of Odawara in 1590 and Tokugawa Ieyasu’s subsequent entry into the Kanto region.
Structure and Remains of Yamazaki Castle (Katori City)
Layout and Structure
Yamazaki Castle in Katori City is built on the western edge of a plateau where the Choji settlement is located. It is a small hill castle with an elevation of approximately 32 meters and a relative height of approximately 27 meters.
The basic structure of the castle is close to a single enclosure, with one enclosure considered to be the main enclosure, surrounded and defended by earthworks and moats. This type of structure is typical of small castles built by local lords during the medieval period.
Existing Remains
Currently, the following remains can be confirmed at the Yamazaki Castle site:
Earthworks
Earthworks remain in two directions, west and south, at the southwest corner of the main enclosure. They are about 1-2 meters high and retain remnants of the defensive facilities of the time. The earthworks are relatively well-preserved, and their shape as castle remains can be clearly observed.
Enclosures (Kuruwa)
A large enclosure exists in the southwest corner, which is believed to be the main enclosure. The flat area is currently used as the grounds of Sobako Shrine. A small enclosure exists in the northwest corner, where the shrine building of Sobako Shrine stands.
Moat
A moat dividing the plateau can be seen. Moats were important defensive structures for castles, preventing enemy intrusion and clearly defining the castle area.
Sobako Shrine
Sabako Shrine is located at the Yamazaki Castle site. The founding date of the shrine is unknown, but it is believed to have been established on this site after the castle was abandoned. The shrine grounds utilize the castle’s main enclosure, allowing visitors to observe the castle remains while paying their respects.
History of Yamazaki Castle (Noda City)
Okabe Nagamori and Castle Construction
Yamazaki Castle in Noda City was built in 1590 (Tensho 18) by Okabe Nagamori. This year marked a historical turning point: Toyotomi Hideyoshi’s siege of Odawara, the fall of the Hojo clan, and Tokugawa Ieyasu’s entry into the Kanto region.
Okabe Nagamori was a hereditary retainer of Tokugawa Ieyasu and held the title of Naizen-no-kami. Upon Ieyasu’s entry into the Kanto region, he was granted 12,000 koku in Shimosa Province and built Yamazaki Castle as his base for governing the territory.
A Castle of Only One Year
Yamazaki Castle was abandoned just one year after its construction, in 1591 (Tensho 19). This was because Okabe Nagamori built Tsutsumidai Castle in the same Noda City and moved his residence there.
Tsutsumidai Castle was larger in scale than Yamazaki Castle and is thought to have been located in a more suitable location for governing the territory. Yamazaki Castle was hastily constructed as a temporary base, and its role quickly ended once Tsutsumidai Castle was completed as a full-fledged residence.
The Later History of the Okabe Clan
Okabe Nagamori was transferred to the Kano Domain in Mino Province in 1601 (Keicho 6), leaving Noda. The Okabe clan subsequently served in the Kano Domain, Kishiwada Domain, Annaka Domain, and other domains, continuing as a daimyo family until the end of the Edo period.
The Current State of Yamazaki Castle (Noda City)
Kaifuku-ji Temple and the Castle Ruins
Currently, a temple called Kaifuku-ji stands on the site believed to be the ruins of Yamazaki Castle in Noda City. The temple grounds are several meters higher than the road to the north, giving it a castle-like atmosphere, but no clear castle remains are preserved.
It is believed that defensive structures such as earthworks and moats have been lost due to long-term development and changes in land use. However, observing the microtopography, traces of the former castle can be seen in the flat areas and elevation changes on the plateau.
Disappearance of Remains
Given that Yamazaki Castle was abandoned after only one year of use, and that development progressed significantly after the early modern period, it’s understandable that very few remains are left. Castles used for only a short time rarely underwent large-scale construction, and tend to deteriorate more easily after abandonment.
Highlights of Yamazaki Castle
Highlights of Yamazaki Castle in Katori City
Side of Sobako Shrine
Side of Sobako Shrine, located within the castle’s main enclosure, offers a tranquil space that evokes a sense of history. As you pray, becoming aware of the castle’s former terrain beneath your feet allows you to feel the romance of history.
Clear Earthwork
The earthwork remaining in the southwest corner is a valuable relic that allows you to actually see a defensive structure from a medieval castle. Its height and shape provide insight into the castle-building techniques of the time.
Traces of a Moat
The moat dividing the plateau is an important relic that demonstrates the castle’s defensive measures. By carefully observing the changes in the terrain, you can understand the location and scale of the moat.
Surrounding Topography Walking around the castle ruins allows you to understand the topographical conditions under which the castle was built, such as the difference in elevation between the plateau and lowlands, and its relationship with the water system.
Highlights of Yamazaki Castle in Noda City
Kaifuku-ji Temple Grounds Although no remains exist, visiting the grounds of Kaifuku-ji Temple allows you to imagine that a castle once stood here.
Plateau Topography The topography of the temple grounds, which is higher than the surrounding roads, indicates that the castle was built on a plateau.
Historical Imagination You can feel the transience of a castle that was abandoned after only one year, and the spirit of the historical turning point of Tokugawa Ieyasu’s entry into the Kanto region.
Access and Visiting Information
Access to Yamazaki Castle (Katori City)
Location
Omishiro, Choji, Katori City, Chiba Prefecture (Sawataka Shrine)
Public Transportation
Approximately 15 minutes by car from Omigawa Station on the JR Narita Line. Access by public transportation is inconvenient, so using a private car is recommended.
By Car
Approximately 25 minutes from the Daiei IC on the Higashi-Kanto Expressway. Parking is available near Sawataka Shrine.
Landmark
Aim for Sawataka Shrine. The shrine grounds are the castle ruins.
Access to Yamazaki Castle (Noda City)
Location
Yamazaki, Noda City, Chiba Prefecture (Kaifuku-ji Temple)
Public Transportation
Approximately 20 minutes on foot or 5 minutes by car from Noda-shi Station on the Tobu Noda Line.
By Car
Approximately 15 minutes from the Nagareyama IC on the Joban Expressway. Parking is available at Kaifuku-ji Temple.
Landmark
Aim for Kaifuku-ji Temple. The entire temple grounds are considered to be the site of the castle.
Points to Note When Visiting
Both castle ruins are located within the grounds of shrines and temples. Please observe the following points when visiting:
- Observe proper etiquette as a visitor and observe quietly.
- Do not enter private property or restricted areas.
- Do not damage the remains or collect plants.
- Always take your trash with you.
- Take photographs within reasonable limits.
Nearby Castles and Tourist Spots
Castles around Katori City
Omigawa Castle
A castle located in Omigawa, Katori City, where a member of the Chiba clan served as lord. It was an important base controlling water transport on the Tone River. It is currently maintained as Shiroyama Park.
Katori Shrine
The head shrine of all Katori shrines nationwide, and has been revered since ancient times as the Ichinomiya (first-ranked shrine) of Shimosa Province. It also has deep ties to the Iizasa clan, who are said to have built Yamazaki Castle.
Castles around Noda City
Sekiyado Castle
Located at the confluence of the Tone River and Edo River, it was a strategically important castle connecting northern Kanto and Edo (present-day Tokyo). The Sekiyado Castle Museum now stands on the site.
Tsutsumidai Castle
This castle was where Okabe Nagamori moved his residence from Yamazaki Castle. Located in Tsutsumidai, Noda City, very few remains of the castle survive.
Kanoi Castle
This castle was located in Higashi-Kanoi, Noda City, and was ruled by a member of the Chiba clan.
Major Castles in Chiba Prefecture
Numerous castle ruins remain in Chiba Prefecture.
Sakura Castle
Located in Sakura City, adjacent to Chiba City, this Edo period castle was extensively renovated by Doi Toshikatsu. Currently, it is maintained as Sakura Castle Ruins Park, and remnants such as earthworks and dry moats are well preserved.
Hon-Sakura Castle
This castle, spanning Shisui Town and Sakura City, was the base of the Chiba clan. The castle remains from the Sengoku period are well-preserved and it is designated a national historic site.
Otaki Castle
Located in Otaki Town, Isumi District, this castle is known for being the residence of Honda Tadakatsu. Currently, a replica keep has been built and is open to the public as the Otaki Castle Branch of the Chiba Prefectural Central Museum.
Historical Significance of Yamazaki Castle
Yamazaki Castle in Katori City as a Medieval Castle
Yamazaki Castle in Katori City is important as a typical example of a local lord’s castle in Shimosa Province during the Sengoku period. While not a large-scale castle, it is a valuable historical site that shows how local samurai established their bases and governed their territories.
Its connection to the Iizasa clan, a family that produced swordsmen, is also interesting and offers insightful information for considering the relationship between martial arts and castles.
Yamazaki Castle in Noda City as an Early Modern Castle
Yamazaki Castle in Noda City was a short-lived castle, abandoned after only one year, but it is important as an example of castle policy during the historically pivotal period of Tokugawa Ieyasu’s entry into the Kanto region.
It reveals a rational approach to territorial management: granting territories to hereditary vassals, having them quickly build castles to establish a system of control, while simultaneously relocating without hesitation if a more suitable base was found.
Yamazaki Castle and the Castle Culture of Chiba Prefecture
Chiba Prefecture is a region where numerous castles were built from ancient times to the early modern period. It was divided into three provinces: Shimosa, Kazusa, and Awa, each with its own unique history.
During the Sengoku period, powerful daimyo such as the Chiba and Satomi clans vied for power, and many branch castles were built. Furthermore, due to its geographical location facing major rivers such as the Tone River and Edo River, as well as the Pacific Ocean and Tokyo Bay, many castles existed to control water and maritime transport.
Both Yamazaki Castles can be positioned within the context of Chiba Prefecture’s castle culture as archaeological sites exhibiting characteristics of different periods: the medieval and the early modern era, respectively.
Challenges in Castle Research and Preservation
Lack of Historical Materials
Regarding Yamazaki Castle (especially in Katori City), there are few reliable historical materials, and many aspects of its construction date, lord, and history remain unclear. It is hoped that further discoveries of historical materials and archaeological investigations will shed light on these details.
Preservation of Remains
Yamazaki Castle in Katori City is somewhat protected by its use as part of the grounds of the Sobatake Shrine. However, no proactive preservation measures are being taken, and the risk of natural collapse and development always exists.
Yamazaki Castle in Noda City has already lost almost all of its remains and is currently in the stage of document preservation.
Need for Public Awareness
It is important to widely publicize the existence of Yamazaki Castle as a regional historical heritage site and to help people understand its value. Public awareness activities are needed, such as installing information boards and utilizing the sites in local history education.
Summary
Yamazaki Castle in Chiba Prefecture is actually two separate castles located in Katori City and Noda City. Katori City’s Yamazaki Castle retains remnants such as earthworks and moats as a castle of a local lord during the medieval period, while Noda City’s Yamazaki Castle is a fleeting castle that existed for only one year during Tokugawa Ieyasu’s time in the Kanto region. Each castle holds distinct historical significance.
Neither castle is large-scale, but they are important historical sites for understanding Chiba Prefecture’s castle culture. When visiting, it is recommended to understand the historical background and characteristics of each castle and reflect on the region’s history while exploring.
Chiba Prefecture also boasts many other noteworthy castles, including Sakura Castle, Hon-Sakura Castle, and Otaki Castle. Why not take this opportunity to experience Chiba Prefecture’s rich castle culture?
