Japan Castle Explorer: Nagurumi Castle -Beginning of the end of Hojo clan-

Nagurumi Castle

-Beginning of the end of Hojo clan-

Overview

Name: Nagurumi castle / Nakurumi castle (Nagurumi-jo / Nakurumi-jo)
Alias:
Place: Shimotsu Minakami town, Gunma

Location: 36.670133022515785, 138.99103283989353
Type: Flat castle
Built: Originally 15th century, expanded in 16th century
Remaining remnants: Clay walls and dry moats
Title: 100 more famous Japanese castles

Brief History

Nagurumi castle (名胡桃城) is located at right bank of river terrace of Tone-gawa river, at 10 kilometer northwest of Numata castle. This place is where Tone-gawa river, the longest river of Japan formed Kanto plain runs up from Pacific ocean faces Mikuni mountains.

Just up from the castle Tone-gawa river divides into main stream and Akaganigawa-river, and two valleys formed by both rivers had been used as communications routes between Kanto plain and Niigata area across mountains. The one is Mikuni kaido road which runs along with Akatanigawa river and passes Mikuni-toge pass as current Route 17, and another goes up northward with main stream and climbs tough slope toward Shimizu-toge pass becomes Route 291, even though collapsed and becomes off limit now. Castle site faces at the merging point of these two routes, and it was an important place for communication.

Origin of Nagurumi castle

Nagurumi castle was originally built by Numata clan, which was the lord of Numata area, at the end of 15th century. In the middle of 16th century, Numata clan once obeyed to Hojo clan, the warlord of Sagami province (Odawara prefecture) and expelled Yamanouchi-Uesugi clan, the governor of Kozuke province (Gunma prefecture), but Kenshin Uesugi (1530-1578), the warlord of Echigo province (Niigata prefecture), retrieved Kouzuke province from Hojo clan and managed.

After the death of Kenshin, at the internal conflict between two adopted sons of Kenshin, Kagekatsu Uesugi (1556-1623), gave territory at Kozuke province to Katsuyori Takeda (1546-1582), the warlord of Kai province (Yamanashi prefecture) as a reward of support. Kagekatsu Uesugi allied with Katsuyori Takeda and won this internal conflict, then left the province to Takeda clan. On the other hand, looking at the decline of Uesugi clan, Hojo clan made pressure to Kozuke province.

Seizure by Sanada clan

Under such circumstance, based on the order from Katsuyori Takeda, Masayuki Sanada (1547-1611), a general of Takeda clan who already captured Iwabitsu castle (Gunma prefectre), tried to change local lords including Shigenori Suzuki (1547-1589), the lord of Nagurumi castle. This plot was successful and Nagurumi castle turned to Takeda clan. Masayuki continuously placed Shigenori Suguki as a commander of Nagurumi castle.

Masayuki used Nagurumi castle as a bridgehead to attack Numata castle, the most important castle in the north part of Kozuke province, and utilizing internal conflict of Numata clan, Masayuki finally captured Numata castle in 1580. By capturing Numata castle Sanada clan expanded their territory and military power, and this became a basis for survival of Sanasa clan in chaotic status after the ruin of Takeda clan in 1582.

But Numata clan originally subordinated to Hojo clan, which recognized themselves as a ruler of Kanto region and hoped to seize whole part of Kanto plain. Numata area became a disputed area between Sanada clan and Hojo clan, then Sanada clan strengthened Nagurumi castle along with Numata castle to protect against the attack of Hojo clan.

Structure of Nagurumi castle

Nagurumi castle is built at a long and narrow height of 200 meter long and 50 meter width separated both side by deep valley. Main body of the castle is a combination of three areas stand in line, it mean third area, secondary area and central area from the root. These areas are connected with narrow bridge, and even though expected battle front is the root of the height, to enable protracted battle, both side of each area is protected by secure gate.

At the ahead of central area, there are several small area such as Sasaguruwa or Monomi along with the ridge. These areas were built to prevent the attack from the tip of the edge climbing sheer slope, and also to bring water from a creek at a valley. At the north of main ridge spreads east and west ward, there is an independent large area named Hannya-kaku. There is no connecting route between main ridge and this front fort, and this area might be used as a camping and storage place in normal time.

Hojo clan made every effort to let Sanada clan to release Numata area by combination of physical attack and negotiation. At the alliance between Hojo clan and Ieyasu Tokugawa (1543-1616), the warlord of Mikawa province (eastern part of Aichi prefecture) and once became the master of Sanada clan in 1584, the cession of Numata area to Hojo clan became the condition. But this was decided without acceptance of Masayuki Sanada, then Masayuki left Tokugawa clan and beat Tokugawa army at the first battle of Ueda castle in 1585.

Sudden capture by Hojo clan

In 1589, under the coordination of central ruler Hideyoshi Toyotomi (1537-1598), it was decided to divide two third of Numata area including Numata castle and transfer to Hojo clan, but one third of area including Nagurumi castle remained as Sanada territory. Hojo clan once accepted this plan and seemed to subordinate to Toyotomi government.

But Hojo clan was quire dissatisfied with this plan. In addition to their hope as a ruler of Kanto region, from practical view, as long as Nagurumi castle remains at Sanada clan, Hojo clan could not secure the border against Kagekatsu Uesugi now subordinated to Hideyoshi.

Just four month after the division of Numata terriotry, Kuninori Inomata (?-?), a commander of Minowa castle under Ujikuni Hojo (1541-1597) who was a regional commander of north Kanto area at Hachigata castle (Saitama prefecture), made sadden attack to Nagurumi castle using trick to lure Shigenori Suzuki out of the castle.

Due to a surprise attack and absence of the commander, Nagurumi castle easily fell against Hojo army, and Shigenori Suguki killed himself shaming this fact. It was said that this was an arbitrarily and mindless action of local general, but could be under the order or agreement of Hojo family. Hojo plan might planned to make it as an accomplished fact.

Beginning of the end of Hojo clan

However, this action was a serious infringement to the authority and order of Hideyoshi, and becomes an excuse to ruin it. Even though Hojo clan apologized that this was a accident, furious Hideyoshi decided to subjugate Hojo clan and raised army of 200,000 solders in March 1590.

Facing this situation Hojo clan besieged at Odawara castle, a secure rmain base of them, but after the encirclement of three months, Hojo clan lost most part of their territory surrendered to Hideyoshi and became an end. Utilizing this situation Hideyoshi forced lords in Tohoku region to subordinate to him, and unification of Japan was completed. After the battle Nagurumi castle was abolished

Now no building exists but major part of structure of the castle well remains good. Recently the ruin is reformed and shows its shape more clearer, even though losing former nostalgic atmosphere. Even though it is not so large castle, as a beginning of the end of Hojo clan and final unification of Japan, Nagurumi castle leaves mark on people.