You can realize the Mori Clan’s long history by walking along the tour route.
Later History
After Yoshida-Koriyama Castle was abandoned, the Asano Clan managed to own its area during the Edo Period. This was because the Mori Clan’s territory had been reduced due to the their lost in the Battle of Sekigahara in 1600. The Asano Clan destroyed the stone walls of the castle after the Shimabara Rebellion in 1637. The Tokugawa Shogunate ordered the lords in western Japan to do it so that even abandoned castles would not be reused by other rebels.
By contrast, the grave of Motonari Mori, which was built at part of the castle by his grandchild, Terumoto Mori, has been maintained. The Asano Clan allowed the lord and warriors of the Choshu Domain by the Mori Clan to pay a visit to the grave. As a result, warriors of other domains also visited it as the holy spot for a great warlord. After the Meiji Restoration, the grave was developed further, gathering the graves of other ancestors of the Mori Clan probably because the Choshu Domain was one of the victorious clans of the restoration. The castle ruins have been designated as a National Historic Site since 1940.
Features
Going to Entrance of Castle Ruins
Today, if you drive to the area around the ruins of Yoshida-Koriyama Castle, you will find some names of the local area like Katsura and Fukuhara. They are the origins of the Mori Clan’s senior vassals until the end of the Edo Period. History fans might be excited to just see them.
The map around Yoshida Town, Akitakada City
There is the tour route which is recommended by officials. Its starting point is the shrine gateway of Motonari’s grave, beside the parking lot at the foot of the mountain. If you walk along the approach towards the grave for a while, you will reach it. This may be the most developed place in the castle ruins as the holy spot. There is also Toshunji Temple Ruins which was established by Terumoto there and eventually moved to Hiroshima, Hagi and Yamaguchi with the lords of the Mori Clan.
The map around the castle
Trail on Ridge of Mountain
You can climb the trail to the top of the mountain from there, on one of its six ridges. It is basically a long trek which takes about 30 minutes to reach the top. You may find some ditches dividing the enclosures or wild animals like deer. Be careful not to provoke them.
Enclosures on Top of Mountain
You will eventually arrive at the ruins of Okurayashiki or the Storehouses below the top. The top consists of three tiered enclosures of the Main, Second and Third. The six ridges spread from the top which also have so many enclosures.
You will find countless stones collapsed which lie around the Storehouses Ruins. It is thought that this was caused by the Asano Clan following the shogunate’s instruction after the Shimabara Rebellion. These stones have been left there for nearly 400 years. However, if you walk around the wall of the Third Enclosure, you will notice some stone walls remaining as they were.
You can also walk around some enclosures on the six ridges such as Tsurii or the Deep Well, Umaya or the Stable, and Kamaya or the Kitchen. There will be a sign warning visitors not to enter that unstable area. Please make you don’t enter that area since it’s very unstable and could cause the land to collapse. Watch your steps as they are reclaiming to nature.
Yoshida-Koriyama Castle was located in Aki Province which is modern day the western part of Hiroshima Prefecture. It was also located in a central mountainous area in the Chugoku Region. It started off as a small mountain castle on one ridge of Koriyama Mountain, which was built by a local lord of the Mori Clan sometime in the Middle Ages. The lord of the clan in the Sengoku Period, Motonari Mori developed the castle covering the whole mountain as he governed almost all the region, he became a great warlord.
The range of Aki Province and the location of the castle
The Mori Clan had been basically a typical local lord which governed Yoshida manor since the 13th Century. As time passed by, their relatives became the clan’s senior vassals such as the Fukuhara and Katsura Clans. Even in the beginning of the 16th Century during the Sengoku Period, the lord of the clan lived in the small Yoshida-Koriyama Castle while the senior vassals lived in their own castles or halls. On the other hand, they had a strong allegiance. This was one of the reasons why they were finally successful in the region.
The relief map around the castle, the home bases of the senior vassals were in different places from the castle
Motonari has many Difficulties
When Motonari first entered Yoshida-Koriyama Castle to become the lord of the clan in 1524, the situation was already bad. The previous lords all died young, as a result, the power of the clan continued to decrease. In addition, the Aki Province was divided by about 30 small local lords like Motonari. Meanwhile, strong warlords were growing in power as the Ouchi Clan in Suo Province, west of Aki, and the Aamago Clan in Izumo Province, north of Aki. The local lords in Aki had to support either clan, otherwise, they would have been defeated. The Mori Clan supported the Amago Clan, however, the clan tried to remove Motonari from being the successor and supported another person whom they can easily control. However, Motonari somehow survived with his senior vassals’ support.
To survive under these difficult situations, Motonari acted like a mediator, not a ruler, in his province. For example, he proposed making a peace treaty with the competitive Shishido Clan in his province by marrying his daughter with the clan’s successor. The clan eventually became another senior vassal of Motonari. He also made alliances with local lords in Aki and Bingo (east of Aki) Provinces with a round-robin contract. A round-robin contract is an equal opportunity for everyone involved with no true leader. He always managed to persuad his three son’s Takamoto, Motoharu and Takakage to be united for the clan’s prosperity (That would create the popular episode, called Three Arrows, sometime later. It refers that Motonari tried to demonstrate the strength of teamwork by using arrows. First, he asked them to break one arrow which was easy. However, when he asked them to break all three arrows at the same time, it was impossible. This was to show his 3 sons that working together was better than working independently.). After that, he sent Motoharu and Takakage as the successors of the Kikkawa and Kobayakawa Clans which also became his relatives. However, he sometimes decided to fight, for instance, when he defeated his senior vassal, the Inoue Clan because they got out of control.
A big crisis came to Yoshida-Koriyama Castle in 1540 after Motonari changed his allegiance from the Amago Clan to the Ouchi Clan. The Amago Clan with about 30 thousand troops surrounded the castle in September. The castle seemed to look small, but Motonari was besieged with about 8 thousand people including warriors and farmers for 4 months, waiting for the reinforcement from the Ouchi Clan. It finally came in December before the Amago troops had to withdraw. This failure of the Amago Clan was said to be the first sign of their destruction which was done in the battle of Gassan-Toda Castle in 1566 by Motonari.
Retainers gather on Whole Mountain
After that, Motonari became a great warlord through many battles, schemes and tricks, such as the Battle of Miyajima against the Sue Clan which followed the Ochi Clan in 1551. During his enterprise, he appointed the his son, Takamoto to be the new leader in 1546, but he still had the power. He moved from the ridge where the castle was first built to the top of the mountain, which would be called the Main Enclosure. Takamoto continued to live in the ridge, which would be called Honjo or the Main Castle, instead of Motonari. However, he eventually moved closer to Motonari by building a new enclosure because it was tough for him to communicate with his father by coming and going. Other retainers also got together on the mountain, as a result, the castle had about 270 enclosures over the mountain as the clan got more power.
Motonari’s grandchild, Terumoto moves to Hiroshima
After the deaths of Takamoto in 1563 and Motonari in 1571, Takamoto’s son, Terumoto Mori followed them. He also improved and modernized the castle by building stone walls, however, he built and moved to his new home base, Hiroshima Castle in 1591. Yoshida-Koriyama Castle was eventually abandoned.
Ouchi Clan Hall was the homebase of the clan which had great power in western Japan in the Middle Ages. Konomine Castle was a mountain castle near the hall, which the clan built during their last years. The Ouchi Clan was originally an official family of the local government in Suo Province which is modern day part of Yamaguchi Prefecture. The clan got power by supporting the Ashikaga Shogunate in the 14th Century. As a result, the clan became the governors of several provinces in western Japan, including Suo and Nagato as their core, which was equal to Yamaguchi Prefecture. They had a complex relationship with the Shogun. For example, Yoshihiro Ouchi, the lord of the clan in the late 14th Century was given 6 provinces by the Shogun, Yoshimitsu Ashikaga. However, he was beaten and killed by the shogunate in the Oei Rebellion in 1399. That’s because the shogunate wanted to rely on, but sometimes feared the power of the Ouchi Clan.
The range of Suo Province and the location of the castle
The relief map around the castle
Ouchi Clan Hall was first built by Yoshihiro’s father, Hiroyo after he set his homebase at Yamaguchi in 1560. Provincial governors often stayed in Kyoto at that time, so they brought the ways of life and cultures from Kyoto when they went back to their homebase. The hall was said to be a typical example of it, being on a square enclosure which was nearly 200m on one side, surrounded by earthen walls and water or dry moats. Not only did it have the Main Hall, but it also had at least three different gardens like a pond garden and a dry landscape or Karesansui, emulating the shogun’s palace. The hall was eventually developed as the clan gained more power, and even a villa was built called Tukiyama Hall in the north. The Yamaguchi town around the hall was also developed and was often called Western Kyoto.
The Ouchi Clan continued to grow in power every generation even after they lost the battle in 1399. Norihiro Ouchi, the lord in the middle 15th Century, added Chikuzen Province which had the international Hakata port to his territory. He started to trade with Ming dynasty in China on behalf of the shogun via the port. The Tsukiyama Hall villa was first built as his retreat. Norihiro’s son, Masahiro fought in Kyoto during the Onin War (1467 to 1477) as the main force of the Western Squad for about 10 years. He also stated his clan was a decedent of a prince of Paekche, making their diplomacy and trading smoother and their authority much stronger.
Ouchi Clan helps Shogun as Great Warlord
During the Sengoku Period after the Onin War, the Ouchi Clan became one of the greatest warlords. The shogun’s power decreased however, and he could not survive without help from a great warlord. For example, the 10th Ashikaga Shogun Yoshitane was banished by the Hosokawa Clan from Kyoto. The banished shogun went to Yamaguchi in 1500, where Masahiro’s son, Yoshioki governed. Yoshioki invited Yoshitane to the Ouchi Clan Hall for dinner. It was called one of the greatest dinners in the Middle Ages, with 32 courses and over 110 dishes. Yoshitane spent 14 hours (from 2pm to 4am) enjoying the dinner that day. In 1508, Yoshioki went to Kyoto with Yoshitane with large troops so that Yoshitane came back to the shogun. The shogun rewarded Yoshioki by giving him Yamashiro Province including Kyoto and a Court noble rank.
The power of the Ouchi Clan reached its peak when Yoshioki’s son, Yoshitaka became the lord. They managed to govern 4 provinces (Nagato, Suo, Chikuzen, and Buzen) and was invading 3 provinces at the same time (Iwami, Aki, and Bingo). Yamaguchi town prospered more while Kyoto continued to be devastated as the power of the shogunate continued to decrease. Many nobles, high priests, and intellectuals managed to escape from Kyoto and Yamaguchi accommodated them. Even, a famous missionary of the Society of Jesus, Francisco Xavier visited the town twice. He gave a tribute to Yoshitaka instead of the Emperor of Kyoto so that he would be allowed to take Christianity to Japan. He seemed to consider Yoshitaka as the king of the country.
Ouchi Clan builds Konomine Castle, but declines
However, a bad sign came to Yoshitaka in 1543. He failed to capture Gassan-Toda Castle, the homebase of the Amago Clan in Izumo Province. There were also internal conflicts between the senior vassals, officers and dependent people from the outside, which Yoshitaka didn’t notice. In 1551, a senior vassal, Takafusa Tou rebelled against Yoshitaka. Yoshitaka managed to escape from Ouchi Clan Hall, tried to board a ship, but failed, and finally he committed Harakiri.
After that, the situation changed significantly. Takafusa helped Yoshitaka’s relative, Yoshinaga being the new lord of the Ouchi Clan, but he was unfortunately defeated in 1555 by Motonari Mori, the lord of Yoshida Koriyama Castle in Aki Province. Yoshinaga built Konomine Castle on a mountain near the hall to protect themselves when he noticed that the Mori Clan could invade his territory. The clan actually did it in 1557, so Yoshinaga stayed in the castle. The castle was good defensively, but could not survive without reinforcement and supply. He managed to escape to another site, but could not do anything to counter, and finally he committed Harakiri like Yoshitaka, which meant the destruction of the Ouchi Clan. It was unknown when the Ouchi Clan Hall was burned down. Konomine Castle was used by the Mori Clan until it was abandoned in 1615 due to the One Castle per Province Law by the Tokugawa Shogunate.