Japan Castle Explorer: Iimori Castle -Prototype of pre-modern regime (3) short peak and sudden fall-

Iimori Castle

-Prototype of pre-modern regime (3) short peak and sudden fall-

Overview

Name: Iimori castle (Iimori-jo)
Alias: Iimoriyama-jo (Iimoriyama castle)
Place: Hojo Daito city, Osaka
Type: Mountain Castle
Built: Around 1520
Remaining remnants: Stone walls, clay walls and moats
Title: 100 more famous Japanese castles

Brief History

Iimori castle (飯森城, also called as Iimori-yama castle) is located over the long ridge of Iimori-yama mountain, one of about 250 meter height from hillside included Ikoma mountains, which prolongs north and southward at the eastern edge of Osaka plain.

Iimori-yama mountain projects westward from the main body of Kawachi mountains, thus it has a panoramic view of Osaka plain from hilltop with sheer slope at west side. Furthermore, the backside of mountain is separated by valleys and ponds from next mountains, thus it becomes a secure fortress only protecting halfway height at southward.

Furthermore, in medieval era, before the movement of Yamato-gawa river, there was a large pond named Fukanoike which connected to Yodo-gawa river and Osaka bay by just blow of Iimori-yama mountain. Because of this, different from now, castle area had a marine transportation from Osaka bay and Seto-Naikai sea, and the road from Kyoto city toward Wakayama area run just below of the castle. Because of these conditions, Iimori-yama area was formerly an appropriate place to manage whole Osaka plain.

Origin of Iimori castle

Because of its geographical conditions small forts might be built at castle place, but genuine castle was built by Nagamasa Kizawa (?-1542), the local lord and retainer of Hatakeyama clan, around 1520. At this time, inside Hosokawa clan which seized experiment of Muromachi Shogunate, two successors Takakuni Hosokawa (1484-1531) and Harumoto Hosokawa (1514-1563).

In 1531, Harumoto Hosokawa and his retainer Motonaga Miyoshi (1501-1532) broke Takakuni Hosokawa at the battle of Daimotsu-Kuzure and established their hegemony. Looking at this Nagamasa Kizawa belonged to Harumoto, but Motonaga and Takakuni became broke for the response to the Shogun Yoshiharu Ashikaga (1511-1550) by the plot of Nagamasa.

Motonaga who became cautions about Nagamasa attacked Iimori castle in 1532, but Nagamasa stirred up Ikko Ikki army formed by believers of Jodo Shinshu, a denomination of Japanese Buddhism. Thousands of army suddenly attacked Miyoshi army from backside, then Motonaga Miyoshi killed himself at Sakai city securely surrounded by the enemy.

Appearance and hegemony of Nagayoshi Miyoshi

Nagayoshi Miyoshi (1522-1564), the successor of Motonaga Miyoshi, waited for the opportunity of revenge and became the retainer of Harumoto Hosokawa. In 1542, Harumoto Hosokawa and Nagayoshi Miyoshi fought at Nagamasa Kizawa who tried to be an independent power, and killed in the battle of Taiheiji.

Harumoto Hosokawa and Nagayoshi Miyoshi who ruined Nagamasa Kizawa became the ruler of the area, but next Ujitsuna Hosokawa (1514-1564), the successor of Takakuni Hosokawa, raised his army against Harumoto and Nagayoshi. Harumoto and Nagayoshi once broke Ujitsuna at the battle of Shariji in 1547.

But next year, Nagayoshi Miyoshi left Harumoto Hosokawa who was the enemy of his father, and allied with Ujitsuna Hosokawa. Both army fought over one year, but in 1549 Nagayoshi broke the army of Harumoto Hosokawa at the battle of Eguchi. Nagayoshi and an ally of Harumoto Hosokawa and Yoshiteru Ashikaga (1536-1565), son of Yoshiharu Ashikaga and next Shogun, faced two years. But finally Nagayoshi beat them in 1551, thus Yoshiteru Ashikaga escaped to Kutsuki area of Omi province in 1551

Compromise with Shogun

It was a great opportunity for Nagayoshi Miyoshi to built his own government, but seven years later Nagayoshi Miyoshi finally coordinated with Yoshiteru and chose to be the highest retainer of Yoshiteru. Nagayoshi had gentle character might not have a braveness to built his own government, and the authority of Shogunate barely remained at minimum level. But considering later history, Nagayoshi Miyoshi missed golden opportunity at this time.

Anyway at this point the government of Nagayoshi virtually established. It was a first centralized government of Japan, uniting the military power of Miyoshi clan held at its territory Awa province (Tokushima prefecture) and Sanuki province (Kagawa prefecture), economic resource of Sakai city, and political authority of Ashikaga Shogunate.

However, in spite of the coordination, Yoshiteru Ashikaga who aimed his direct ruling did not agree with Nagayoshi. Yoshiteru sent many letters to powerful warlords such as Takeda clan or Uesugi clan, coordinate the conflict between the lords and tried to increase the authority of Shogun. Furthermore, Yoshiteru tried to assassinate Nagayoshi but failed each time.

Move of main base to Iimori castle

At that time, Hatakeyama clan which was the governor of Kawachi province (south half of Osaka prefecture) and its retainer Munefusa Yasumi (?-?) who held Iimori castle raised their army against Nagayoshi in 1559. Nagayoshi encircled Iimori castle with large army then Munefusa Yasumi escaped to Yamato province (Nara prefecture), and Nagayoshi captured Iimori castle.

To keep distance from troublesome Shogun and manage his whole territory, Nagayoshi moved his main base from Akutagawasan castle to Iimori castle. Under unstable circumstance, Iimori castle has a good view and connection to the territories of Miyoshi clan such as Awa province or Sanuki province, or Sakai city which was economic source of Miyoshi clan by water transportation, was appropriate as a main base. Nagayoshi significantly reformed Iimori castle as a main base of Miyoshi clan.

Structure of Iimori castle

Iimori castle spread over long and narrow ridge of Iimori mountain prolongs north and south ward. Central area of the castle is a rectangular area of about 50 meter long and 15 meter wide at the top of the mountain. At the north of central area, two similar size terrace was built at the slope in line. The south slope of central area is securely guarded by dry moat and clay bridge.

At the north of core area, north part which consist of round shaped area and surrounding small terraces exist. As this part is surrounded by sheer cliff, this part was not reformed and kept original style of the castle. But several slopes of this part were covered by stone walls, probably to show the authority of Miyoshi clan toward north, the direction of Kyoto city.

On the other hand, South part of the castle had larger terraces used as a ground of temple, to be used as a residential place in peace time and front fort in war time. The south edge of this part was securely protected by dry moat and clay wall, and there might be a main gate had stone walls at both side. Total size of the castle is about 800 meter long and 400 meter wide, and extremely large one at this area.

Short-term peak of Miyoshi clan

Around this time, the territory of Nagayoshi was at the peak, In addition to the original territory such as Awa province, Sanuki province and Awaji province (Awaji island), Nagayoshi already held Settsu province (north part of Osaka prefecture), Kawachi province, Izumi province (south part of Osaka prefecture).

Furthermore, Tanba province (western part of Kyoto prefecture) and Yamato prefecture were captured by Nagayori Matsunaga (?-1565) and Hisahide Matsunaga (1510-1577), the brothers held brilliant talent. At this point, Nagayoshi Miyoshi was the strongest and most wealthy warlord in Japan.

But the peak period of Nagayoshi did not last long. In 1561, Kazumasu Sogo (1532-1561), the younger brother of Nagayoshi and known for his braveness as "Damon Sogo" suddenly died in the ill. Looking at this, under the plot of Yoshiteru Ashikaga, Rokkaku clan which was the lord of Omi province (Shiga prefecture) and Hatakeyama clan once retreated to Kii province (Wakayama prefecture) raised their army against Nagayoshi at the same time in 1562

Victory which was step to fall

Jikkyu Miyoshi (1527-1562), the younger brother of Nagayoshi and good talent for politics and culture, intercepted Hatakeyama army at current Kishiwada city. But assaulted by musket gunners of Negoro mercenaries, Jikkyu died in the battle and was recorded first general killed by the gun in the battle. The south part of the territory collapsed, and Hatakeyama army encircled Iimori castle.

But Iimori castle was a secure castle and bear the attack of enemy. Nagayoshi summoned all army from his territory and prepared counter attack to Hatakeyama army. Because of the plot of Hisahide Matsunaga, Hatakeyama army released Iimori castle and tried to retreat, but was captured by the superior Miyoshi army and suffered severe defeat. As a result of this battle of Kyokoji, Nagayoshi Miyoshi ruined enemy power in Kinki region and established his hegemony.

However, contrary to this victory, Miyoshi clan faced severe troubles and disintegrated. In 1563, Yoshioki Miyoshi (1542-1563) who showed the talent for both of politics and military suddenly died in ill. Nagayoshi in despair heard the rumor on the betrayal of remaining younger brother Fuyuyasu Ataki (1528-1564), who was known as the calm and generous, and killed Fuyuyasu in 1564. It was said as a plot of Hisahide Matsunaga who tried to capture the power in Miyoshi clan, but it is not clear if it is true or not.

Death of Nagayoshi and sudden fall of Miyoshi clan

Nagayoshi fell into loneliness finally died in 1564 at Iimori castle, only in 42 years old. As Nagayoshi and younger brothers died before the growth of their sons, Miyoshi clan lacked the person to pile up the clan. As Yoshitsugu Miyoshi (1549-1573), the adopted son of Nagayoshi, was still young, the trio of important generals of Miyoshi clan and Hisahide Matsunaga managed Miyoshi clan, and killed Yoshiteru Ashikaga.

However, in 1567, Nobunaga Oda (1534-1582), the warlord of Owari province (western part of Aichi prefecture) who also held Mino province (Gifu prefecture) and Ise province (Mie prefecture), marched to Kyoto city with Yoshiaki Ashikaga (1537-1597), the younger brother of Yoshiteru Ashikaga.

Miyoshi clan significantly lost their power by internal conflicts between Hisahide Matsunaga and the trio, thus easily collapsed and evacuated Kyoto city to Nobunaga. Sakai city faced the threat from Nobunaga subordinated to Nobunaga. Nobunaga placed Yoshiaki Ashikaga at new Shogun and established Oda government,

After that Miyoshi clan allied with Yoshiaki Ashikaga who became the enemy of Nobunaga, but in 1573 Yoshiaki Ashikaga was expelled from Kyoto city, and Yoshitsugu Miyoshi killed himself Wakae castle in the siege of Oda army. Now Ashikaga Shogunate and the main stream of Miyoshi clan experienced complex relationship disappeared at the same time.

Prototype ruler prior to Nobunaga Oda

Nagayoshi Miyoshi and Nobunaga Oda were alike trying to establish their government uniting military power, economic resource and political authority. But Miyoshi clan had two upper authority it means Hosokawa clan and Ashikaga Shogunate still had invisible powers.

It was quite difficult to overcome these two powers, and the military power of Miyoshi clan was still insufficient to suppress all opponents of the region Furthermore, the army of Miyoshi clan was still a mixture of small local lord, only united by the talent of Nagayoshi and younger brothers.

Contrary to this, Nobunaga had already overcame and neutralized his upper authority Shiba clan, and could focus to the response to Yoshiaki Ashikaga. Nobunaga had sufficient military power to keep whole Kinki region, and its army were well organized under talented generals. Furthermore, Nobunaga directly held Kyoto city and the residence of Yoshiaki Ashikaga unlike Miyoshi clan.

As Miyoshi clan broke all of old powers in Kinki region and disintegrated, Nobunaga could easily enter the vacant Kyoto city and seize the power. If Nagayoshi and his relative lived longer, the history of Japan might be totally different. Miyoshi government was a prototype of succeeding pre-modern governments, and Nagayoshi paved the way to next generation rulers.

Afterward of castle

After the death of Nagayoshi Iimori castle was held by Miyoshi clan, but Yoshitsugu Miyoshi moved his main base to Wakae castle at the plain. After the fall of Miyoshi clan, Iimori castle might be abolished around 1575.

Now no building remain but structure of the castle well remain on the mountain with ruins of stone walls. Magnificent view of Osaka plain seen from the castle clearly shows the power of Miyoshi clan who temporally seized hegemony at this area. At the same time, Kyoto city is not clearly seen from the castle site, and this also implies the gap between Miyoshi clan and Ashikaga Shogunate which was not overcame to the end.

Access

15 minutes walk from JR West Gakken-Toshi line Nozaki station to hillside entrance at Jigan-ji temple. 20 minutes drive from Daini Keihan Expressway Neyagawa interchange. 30 minutes walk from hillside to hilltop castle.