An admired mountain castle during the Sengoku Period governed by the Miyoshi Clan
Location and History
Mountain Castles during Sengoku Period
In the 16th Century during the Sengoku Period, battles often happened in the Kinki Region of Japan. Warlords usually lived in their halls located in a plain area like Kyoto, and used their mountain castles for emergency. However, it got too dangerous for them then because they couldn’t predict when the next battle would happen. As a result, they started to live in their mountain castles every day. These castles had their halls on the top and strong defense systems. Akutagawa-san Castle was one of the most admired ones in the region.
The location of the castle
Nagaoyshi Miyoshi settled at Castle
The castle was first built in 1516 by Takakuni Hosokawa, a senior vassal of the Ashikaga Shogunate, but it is famous for the home base of Nagayoshi Miyoshi. Nagayoshi came from Awa Province (what is now Tokushima Prefecture) in Shikoku Island working under the Hosokawa Clan. He got power in both politics and military while other retainers of the shogunate conflicted each other. When his power competed with the Shogun, Yoshiteru Ashikaga, Yoshiteru tried to kill Nagayoshi. Nagayoshi banished the shogun from Kyoto and started his own governance in 1553. In the same year, he also settled at Akutagawa-san Castle.
The portrait of Nagayoshi Miyoshi, owned by Juko-in of Daitokuji Temple (licensed under Public Domain via Wikimedia Commons)The portrait of Yoshiteru Ashikaga, owned by the National Museum of Japanese Histories(licensed under Public Domain via Wikimedia Commons)
Mountain with Defense and Authority
The castle was located on the top of Miyoshi-yama Mountain in Settsu province (what is nearly the northern part of Osaka Prefecture), the north of the Osaka Plain. The mountain itself was very defensive being surrounded by Settsukyo Valley in north and west directions. The castle was accessible by road from the east through the ridges and the south through the valley. Nagayoshi himself attacked the castle previously, so he would have realized how strong the castle was.
The relief map around the castle
The imaginary drawing of the castle (from the signboard at the site)
The Main Enclosure had the Main Hall on the top of the mountain. Many other enclosures were around the ridges on the east of the Main Enclosure. The route went alongside these enclosures, and it was controlled by structures such as earthen walls, earthen bridges, dry moats, and alternate entrances. The Main Route also ran on the south of the Main Enclosure. It was very steep and guarded by the Main Gate which had stone walls. The stone walls are thought to also show the authority of the castle, so regarded as one of the earliest examples of castles in Japan to use stone walls intendedly.
The imaginary drawing around the Main Enclosure (from the signboard at the site)The imaginary drawing of the group of the enclosures on the east of the Main Enclosure (from the signboard at the site)The imaginary drawing of the Main Route and the stone walls (from the signboard at the site)
Nobunaga Oda once stayed in Castle
Though Nagayoshi passed the castle to his son and moved to Imori Castle in 1560, Akutagawa-san Castle continued to be used by the Miyoshi Clan as their important castle. In 1568, Nobunaga Oda came to Kyoto to rule the Kinki Region. He once captured and stayed in Akutagawa-san Castle and gave it to his retainer. However, as he proceeded with his unification of Japan, there would be no need for a castle like Akutagawa-san Castle. The castle was later abandoned.
The portrait of Nobunaga Oda, attributed to Soshu Kano, owned by Chokoji Temple (licensed under Public Domain via Wikimedia Commons)
Kokokuji Castle was located in what is now Numazu City, Shizuoka Prefecture. The area of the city was in Suruga Province (now central part of Shizuoka Pref.) which many warlords tried to take over in the 16 Century during the Sengoku Period.
The location of the castle and the range of Suruga Province
The castle was on the southern edge of the hilly terrain of Ashitaka-yama Mountain. There was a marshland to the south, east and west of the castle which was as natural hazard that helped to protect the castle. The castle was built using the natural terrain of the mountain and marshland. The castle was also an important point for transportation. A road at the foot of the mountain called the Nekata Road passed beside the castle. In addition, the Takeda Road close to the castle ran from the Nekata Road to the Tokaido Road at the seaside.
A relief map around the castle
The two roads are still connected to the castle ruins
The castle mainly consisted of three enclosures on the hill in a terraced manner. The Main Enclosure was at the highest, and there was a large deep dry moat behind the enclosure to prevent enemies’ attacks from the north. The castle even had ports on both sides for ships on the marsh.
Part of the illustration of Shinkokuji Castle in Suruga Province, exhibited by the National Diet Library (It is supposed to be Kokokuji Castle)
The castle itself might have been simple but is well known for its history. This is because some history books say that Kokokuji Castle was the first castle for a famous warlord, Soun Hojo to govern. He was one of the earliest warlords in the late 15 Century who supported the Imagawa Clan in Suruga Province. He was given the castle by the clan in 1487. His success story starts at this castle, and he went on to capture a part of the Kanto Region. His descendants followed in his footsteps to capture the other parts of the Kanto Region.
The replica of the portrait of Soun Hojo, owned by Odawara Castle (licensed under Public Domain via Wikimedia Commons)
However, there is no other evidence of the castle existing at the same time as Soun. The first appearance of the castle in a public document can only be traced back to 1549. At that time, Yoshimoto Imagawa ordered that the Kokoku-ji Temple be moved to another location to make space for building a new castle there. What is the truth about the matter? A historian gives us an interesting hypothesis that the castle was a temple called Kokoku-ji when Soun owned it. Kokoku-ji is originally a name of temple (“ji” means temple in Japanese). Kokokuji Castle is thought to be named after the Kokoku-ji Temple.
The statue of Yoshimoto Imagawa at Okehazama Battlefield Park (taken by HiC from photoAC)
The historian suggests another speculation about why the castle was built. A period of peace once came to the area around Suruga Province with Imgawa, Hojo, and Takeda Clans when the castle was built. Castles were basically built for battles, but Kokokuji Castle might have been built for the meeting with the three clans or as a symbol of peace. It is said that the three clans had a conference for their alliance at the Zentokuji-Temple. The temple may have been Kokokuji Caste.
The portrait of Shingen Takeda, the lord of the Takeda Clan at that time, owned by Jimyo-in Temple (licensed under Public Domain via Wikimedia Commons)
Unfortunately, the alliance broke in 1568, while Kokokuji Castle was involved in war. The lords of the castle were rapidly changed several times from the Imagawa Clan to the Hojo, Takeda, Toyotomi, and Tokugawa Clans. As the number of the lords increased, the range of the castle seemed to become larger. In 1601, Yasukage Amano under Tokugawa became the last lord of the castle and the founder of the Kokokuji Domain. He governed the area well, but he ran away from the castle because of trouble between his citizens and others. The castle was finally abandoned when the domain was abolished in 1607.
Yasukage Amano from the Battle of Komaki-Nagakute folding screens (licensed under Public Domain via Wikimedia Commons)
名胡桃事件で有名な城
The castle famous for the Nagurumi Incident
立地と歴史～Location and History
沼田城への橋頭保～Foothold for Numata Castle
名胡桃城は上野国（現在の群馬県）北部にありました。この城は戦国時代の１６世紀後半に大河である利根川西岸の崖の上に築かれました。川を渡った反対側には沼田城があり、そこは関東地方の戦国大名にとっては非常に戦略的な拠点でした。武田氏の配下であった真田氏が沼田城を確保するための橋頭保として1579年に名胡桃城を築き、1580年には実際に沼田城を手に入れました。 Nagurumi Castle was located in the north part of Kozuke Province (what is now Gunma Prefecture). It was built in the late 16th Century during the Sengoku Period, on a cliff near the west bank of a large river called Tone-gawa. At the opposite side across the river, there was Numata Castle which was a very strategic spot for warlords in Kanto Region. The Sanada Clan under the Takeda Clan built Nagurumi Castle in 1579 as a foothold for capturing Numata Castle which actually belonged to Sanada in 1580.
城の位置～The location of the castle
城周辺の起伏地図～The relief map around the castle
名胡桃事件の発生～Nagurumi Incident happens
真田氏はしばらく沼田城を維持していましたが、1589年7月の天下人豊臣秀吉の裁定により、北条氏に引き渡されてしまいます。一方真田氏は、名胡桃城はまだ領土の一部としていました。この裁定は北条が秀吉の臣下になるという条件の下に行われました。1589年11月、豊臣秀吉の命令に逆らい、北条は名胡桃城を占領しました。この事件は名胡桃事件と呼ばれています。真田氏は秀吉に事件のことを訴え、秀吉は激怒し北条を成敗することを決定しました。北条氏は当時最も有力な戦国大名の一つでしたが、この事件は1590年の小田原征伐での滅亡につながります。定説によれば、北条は世の中の流れを見誤ったとされています。 The Sanada Clan held Numata Castle for a while, but the castle was handed over to the Hojo Clan under the decision by the ruler Hideyoshi Toyotomi in July 1589, while Sanada still kept Nagurumi Castle in their territory. The decision was made on condition that Hojo would become a vassal of Hideyoshi. In November 1589, against the instructions of Hideyoshi Toyotomi, the Hojo Clan seized Nagurumi Castle. The incident at the castle is called the Nagurumi Incident. The Sanada Clan appealed it to Hideyoshi who was very angry about it and decided to defeat Hojo instead. The Hojo Clan was one of the greatest warlords at that time, but this incident led to their fall in the Siege of Odawara Castle in 1590. The established theory says Hojo misjudged the current tide.
豊臣秀吉肖像画、加納光信筆、高台寺蔵～The Portrait of Hideyoshi Toyotomi, attributed to Mitsunobu Kano, ownd by Kodaiji Temple（licensed under Public Domain via Wikimedia Commons）
秀吉と真田の陰謀か～Trick by Hideyoshi and Sanada?
しなしながら、歴史家の森田喜明は、この事件は秀吉と真田による謀略であったと反論しています。秀吉が残した手紙によると、彼は既に遅くとも1589年の10月には北条を成敗することを決めていたと言います。秀吉が1589年12月にこの事件のことを北条に問いただした時、北条は平然と、名胡桃城もまた真田から北条に引き渡されたものであり、秀吉に会うための準備を引き続き進めていると答えています。実は、秀吉が名胡桃城を真田側に留めるという裁定内容は、彼から北条への手紙に初めて出てくるのです。更には、発掘調査によれば、名胡桃城跡では戦いや火災があった跡は発見されていません。この新説は実に興味深いものです。 However, a historian Yoshiaki Morita argues that this incident was a trick made by Hideyoshi and Sanada. He says that Hideyoshi had already decided to defeat Hojo at latest in October 1589 according to Hideyoshi’s letters. When Hideyoshi asked Hojo about the incident in December 1589, Hojo answered Hideyoshi calmly that Nagurumi Castle had also been handed over to Hojo by Sanada and they still continued to prepare the meeting with Hideyoshi. In fact, the decision by Hideyoshi to keep Nagurumi Castle on Sanada’s side was shown in his letter to Hojo for the first time. In addition, there is no evidence of a battle or fire in the ruin of Nagurumi Castle according to the excavation team. This new theory is very intriguing.
北条氏政肖像画、当時の北条氏当主、小田原城天守閣蔵～The portrait of Ujimasa Hojo, the head of the Hojo clan at that time, owned by Odawara Castle (licensed under Public Domain via Wikimedia Commons)
いずれにしろ、北条氏が滅んだ後、沼田・名胡桃両城は真田氏のものとなりました。名胡桃城はその後すぐに廃城となります。真田による沼田城の支配が安定し、その役割が既に終わったからです。城の生涯は１０年あまりでした。 Anyway, the fact is that the Sanada Clan owned both Numata and Nagurumi Castles again after the Hojo Clan was defeated. Nagurumi Castle was abandoned soon after that because its role had already ended when Sanada’s governance of Numata Castle became stable. The castle survived for more than ten years.
城の想像図～The imaginary drawing of the castle (現地説明板より～from the signboard at the site)
特徴～Features
自然の地形を生かして築城～Built using Natural terrain
現在、名胡桃城跡は行政によりよく整備されていますが、規模は大きくありません。それは、沼田城を手に入れるための橋頭保という、この城の目的が特定且つ一時的なものだからです。しかしながら、この城が崖から突き出た岬のような自然の地形を生かして作られているのが今でもよくわかります。この地形は、空堀によって三つの主要な郭～主郭、二郭、三郭、に先から元に向かって分かれています。その先には更に２つの郭～ささ郭と物見郭が見張りのために加えられていました。 Now, the ruins of Nagurumi Castle are well developed by officials, but their scale is small. This is because the purpose of the castle, the foothold for capturing Numata Castle, was specific and temporally. However, you can even now see the castle is built using the natural terrain of a shape like a cape sticking out of the cliff. The terrain is divided by dry moats into the three major enclosures – the Main Enclosure, the Second Enclosure, and the Third Enclosure from the top to the bottom. Over the top, two more small enclosures – Sasa-Kuruwa and Monomi-Kuruwa were added to look out.
城周辺の航空写真～The aerial photo around the castle
根元の方には「馬出し」と呼ばれる丸い形で突き出ている防御システムが加えられ、現在でもその形をなぞった線によりわかるようになっています。 At the bottom, a sticking out round shaped defensive position called “Umadashi” was added, the tracing line for the Umadashi shows it now.
馬出しの跡を示す線～The tracing line for the Umadashi system馬出しの想像図～The imaginary drawing of the Umadashi system (現地説明板より～from the signboard at the site)馬出しと三郭～The Umadashi system and the Third Enclosure
主要部分の構造～Structures of Main Portion
これらの郭の間をつなぐ木橋と接続部分が復元されています。それぞれの郭は簡単な櫓とともに高い土塁と今よりずっと深い空堀によって囲まれていました。二郭は大きな郭でいくつかの建物がありました。主郭には城の記念碑が設置されています。ささ郭まで行くことができ、利根川と沼田市域の景色を眺めることができます。 Wooden bridges and zigzagged connecting points have been restored between these enclosures. Each enclosure was surrounded by high earthen walls with simple turrets and much deeper dry moats in the past. The Second Enclosure is the large one where several buildings stood. The monument of the castle is placed on the First Enclosure. You can go as far as the Sasa-Kuruwa Enclosure to have a view of Tone-gawa River and Numata City area.
三郭と二郭の接続部分～The connecting point between the Third Enclosure and the Second Enclosure三郭と二郭の間の空堀～The dry moat between the Third Enclosure and the Second Enclosure接続部分の想像図～The imaginary drawing of the connecting point (現地説明板より～from the signboard at the site)二郭～The Second Enclosure二郭の想像図～The imaginary drawing of the Second Enclosure (現地説明板より～from the signboard at the site)二郭と主郭の接続部分～The connecting point between the Second Enclosure and the Main Enclosure主郭～The Main Enclosureささ郭へ～Going to the Sasa-Kuruwa Enclosureささ郭の想像図～The imaginary drawing of the Sasa-Kuruwa Enclosure (現地説明板より～from the signboard at the site)ささ郭～The Sasa-Kuruwa Enclosureささ郭からの眺め～A view from the Sasa-Kuruwa Enclosure
その他の見所～Other Attractions
城で最も大きな郭は般若郭で、他の郭とは別の並びの所にあります。この郭は、多くの兵士を駐屯されるために使われたと考えられています。現在は、ここに車を駐車できます。 The largest enclosure in the castle called Hannya-Kuruwa is in a different line from the other enclosures. It is thought that this enclosure was used to station a lot of soldiers. You can now park your car at this enclosure.
般若郭～The Hannya Enclosure
城址案内所では城とその歴史のついてより学ぶことができます。もちろん、そこで説明されているのは、この城は決して北条に引き渡されていなかったという定説の方です。 You can learn more about the castle and its history at the information office. Of course, the explanation of the office is based on the established theory that the castle of never handed over to Hojo.
城址案内所～The information office
その後～Later History
名胡桃城は早くに廃城となりましたが、その名はとてもよく知られています。例えば、江戸時代後期の有名な日本の歴史書である「日本外史」には名胡桃事件のことが書かれています。1923年、地元の人々が城の保存会を立ち上げ、1927年には本郭に記念碑を建て、歴史公園として城跡を整備しました。更に最近では、みなかみ町が1992年から2006年までの間、城の発掘を行いました。2015年までに町は、詳細な発掘の成果に基づき土塁や木橋の一部の復元を行い、公園の整備を進めました。城跡は現在、群馬県の史跡に指定されています。 Nagurumi Castle was abandoned earlier, but its name is very well known. For example, a famous textbook for Japanese history in the late Edo Period, called “Nihon-Gaishi”, described the Nagurumi Incident. In 1923, the local people launched the preservation society for the castle and developed the ruins as a historical park building the monument at the Main Enclosure in 1927. In more recent years, Minakami Town excavated the castle between 1992 and 2006. By 2015, the town had developed the park more by restoring part of the earthen walls and wooden bridges according to the details of the achievements of the excavation. The ruins is now designated as a Prefectural Historic Site of Gunma.
本郭にある記念碑～The monument at the Main Enclosure
私の感想～My Impression
名胡桃城は広くもなく、石垣の上の天守のような大きな建物もありませんでした。しかし、戦国大名が築いた無数の城の一例なのです。ほとんどの城は特定の目的のみに作られ、その役目を終えれば廃城となりました。名胡桃城はそのような城だったのですが、有名になったがゆえによく整備された城跡として見ることができるのです。この城は地味ですが有益だと思います。そして実際の歴史を学ぶためによい教材だと思うのです。 Nagurumi Castle was not large and didn’t have large buildings like a Main Tower on stone walls. However, it was an example of an uncountable number of castles warlord built. Most of these castles were built just for their specific roles and abandoned after their roles ended. Nagurumi Castle was one such castle, but we can enjoy seeing its well-developed ruins because the castle has become famous. I think the castle is simple, but useful. It is a good teaching resource for people to learn real history.
城跡の入口～The entrance of the castle ruin
ここに行くには～How to get There
関越自動車道の月夜野ICから約１０分のところにあります。般若郭に駐車場があります。 公共交通機関を使う場合には、上越新幹線の上毛高原駅か、ＪＲ上越線の後閑駅からタクシーに乗ってください。 It takes about 10 minutes driving from Tsukiyouno IC on Kanetsu Expressway. The ruins offer a parking lot in Hannya-Kuruwa enclosure. If you want to go there by public transportation, take a taxi from Jomo-Kogen Station on Joetsu-Shinkansen Super express or from Gokan Station on JR Joetsu Line.
