-Castle of traditional clan repeated downfall and revival-
Name: Seifukuji castle (Seifukuji-jo)
Place: Kanzaki town Kanzaki city, Saga
Type: Mountain Castle
Remaining remnants: Clay walls and moats
Seifukuji Castle (勢福寺城) is built at Shiroyama mountain, one of about 150 meter height from hillside at about 10 kilometer north-northwest from Saga city. Castle site is at the south edge of Sefuri mountains which spreads along the border of current Saga prefecture and Fukuoka prefecture, and directly faces Saga plain. Nagasaki Jidoshado Expressway runs along this border of mountains and plains, and penetrates Shiroyama mountain by tunnel.
Shiroyama mountain itself is not so large one, but having Kawarake-yama mountain which was worshiped as sacred place at backside, flat plateau protected by Jobaru-gawa river and its tributary at southern hillside, and small hills suitable for front side fort. Furthermore, castle site has a good scenery of whole Saga plain, and also exists at the mountain road from Fukuoka plain to Saga plain passing Sefuri mountains by Mise-toge pass and Ouchi-toge pass. Because of these reasons, Seifukuji castle was a suitable place to use as a main base of local lord.
Origin of Seifukuji Castle
It is said that Seifukuji castle was built by Naouji Isshiki (?-?), who was a distant relative of Muromachi Shogunate and was appointed as the general governor of Kyushu island in 1353. After the fall of Kamakura Shogunate in 1333 by Emperor Godaigo (1288-1339) and Takauji Ashikaga (1305-1358), Emperor and Takauji broke then built South Court and North Court respectively and fiercely fought over 50 years. While North Court supported by Takauji was generally dominant, Takauji also conflicted with his younger brother Tadayoshi Ashikaga (1306-1352).
This complex situation was also brought to Kyushu island. Emperor Godaigo sent his son Prince Kaneyoshi (1329-1383) to Kyushu island, and captured south half of Kyushu island being supported by local lords such as Kikuchi clan. On the other hand, Shoni clan which traditionally managed north half of Kyushu island belonged to Tadayoshi Ashikaga.
Disorder of Kyushu island
Looking at this situation, Takauji Ashikaga sent his distant relative Isshiki clan to Kyushu island to conquer it, and landed Isshiki clan built Seifukuji castle as their main base against both of Prince Kaneyoshi and Shoni clan. But being surrounded two strong enemies, Isshiki clan could not manage their territory then returned to central area. After Isshiki clan, Kikuchi clan once held Seifukuji castle under Prince Kaneyoshi, and South Court army once captured Hakata city in 1361.
Being deprived most important city in western Japan, Muromachi Shogunate sent talented general Sadayo Imagawa (1326-1420) as a general commander of Kyushu island. Sadayo gathered local lords including Shoni clan and broke South Court army and captured Hakata city in 1372.
But being feared his power and talent, Sadayo was suddenly lost his position in 1395, and Shibukawa clan which was also a relative of Muromachi Shogunate succeeded his position and was supported by Ouchi clan, which was the strong warlord of Suo and Nagato province (Yamaguchi prefecture).
Traditional clan once held Hakata city
Looking at this change, Shoni clan once followed to Sadayo Imagawa tried to recover their former territory including Hakata city. Shoni clan was a traditional clan which was said as the descendant of Hidesato Fujiwara (?-?) who was an ancestor of the lords of Kyushu island such as Otomo clan, Ryuzoji clan or Tachibana clan. After the establishment of Kamakura Shogunate, Shoni clan was appointed as "Dazai Shoni", the vice minister of Dazaifu city used the name of their role as surname.
At the invasion of Chinese Yuan Dynasty and Korean Koryo empire in 1274 and 1281, as Dazaifu capital became the target of attack then Shoni clan faced this invasion as front commander. But being suffered severe damage, Shoni clan stroke back this attack along with samurais of Kyushu island, then grew into the governors of north half of Kyushu island.
After the fall of Kamakura Shogunate, Shoni clan divided into both supporters and significantly lost their power and territory including Hakata city, and Muromachi Shogunate sent their representative Sadayo Imagawa (1326-1420) to manage Kyushu island. The leader of Shoni clan once followed Sadayo but was assassinated by Sadayo, and after the return of Sadayo, Ouchi clan which was the advanced into north part of Kyushu island in turn.
Endless battle against Ouchi clan
Under such situation, Shoni clan started their endless battle against Ouchi clan, and once captured Hakata city expelling Shibukawa clan, In response to this, Muromachi Shogunate ordered Moriharu Ouchi (1377-1431), the leader of Ouchi clan, to punish Shoni clan. But Shoni clan won at the battle against Moriharu Ouchi and killed him at battlefield. It seemed Shoni clan recovered their former territory and glory.
However, in 1433, Mochiyo Ouchi (1394-1441) who was the son of Moriharu Ouchi, landed Kyushu island to make revenge against Shoni clan under the order of Muromachi Shogunate. Shoni army was broke by Ouchi army then leaders of Shoni clan such as Mitsusada Shoni (1394-1433) or Suketsugu Shoni (?-1433) died at the battlefield.
Shoni clan experienced their first ruin, but Yoshiyori Shoni (1421-1441) who escaped to So clan which was the lord of Tsushima island survived and started his activity to restore the clan. Noriyori Shoni (1426-1469) who was the younger brother of Yoshiyori Shoni was once forgiven by Muromachi Shogunate and temporally recovered Hakata city but lost by the pressure of Ouchi clan.
Continuous downfall and recovery
At the battle of Onin from 1467 to 1477, looking at the absence of Ouchi clan which sent their army to Kyoto city, Yoshiyori raised his army against Ouchi clan and attacked Hakata city. But Shoni army was defeated by remaining Ouchi army and was reversely captured their main base Takaso castle then Noriyori killed himself at Takaso castle. Shoni clan experienced their second ruin.
However, Masasuke Shoni (1441-1497), son of Noriyori Shoni, escaped to So clan at Tsushima island again and recaptured Hakata city at the absence of Ouchi army in 1469. As Ouchi army was bound at Kyoto city by the battle of Onin, Masasuke recovered former territory of Shoni clan, and advanced into south part of Hizen province including Seifukuji castle utilizing internal conflict of local lord Chiba clan.
But loss of Hakata city was not acceptable for Ouchi clan. After the cease of the battle of Onin, In 1496, Ouchi clan sent large army to Kyushu island to recover Hakata city, then broke Shoni army around Hakata city and intruded into Hizen province. Masasuke Shoni and his son Takasuke Shoni (?-1497) were attacked at Seifukuji castle and escaped to neighbor castle but died in the battle, then Shoni clan experience their third ruin.
However, Sukemoto Shoni (1489-1536), another son of Masasuke, who was hidden by former retainers grew up and restored Shoni clan, being supported by former retainers. Masasuke Shoni grew his power from Seifukuji castle, and rejected the attack of Ouchi clan in 1530, under the support of Iekane Ryuzoji (1454-1546), the grand-grandfather of Takanobu Ryuzoji (1529-1584) who later became the strong warlord of Hizen province and feared as "the bear of Hizen". Seifukuji castle might be reformed as a main base of Shoni clan now became the leader of Hizen province.
Structure of Seifukuji castle
Seifukuji castle roughly consist of hilltop area, halfway fort and hillside residence. Hilltop area itself is divided into older south half and newer north half separated by deep dry moat. South half of the castle consist of linearly lined several narrow and long terraces. The south edge might be a watching place toward southward, and the triangle shaped area at the north edge might be the central area of the castle, with a broad clay wall might be used as a basement of watchtower.
North part might be built at later period, with clearer clay walls, folded traffic line and numerous vertical dry moats. Different from south half, terraces are built at both side slope, and ruin of stone wall slightly remains. Total length of hilltop area is about 500 meter long, and well shaped terraces shows the power of Shoni clan even though ruined many times and wandered.
On the gentle ridge connects hillside and hilltop area, front forts consists of several flat terraces continues from halfway to hillside. They are mainly simple flat space but partially protected by dry moats. At the southeast of Shiroyama mountain, ruin of residential area including square places used as the residence of the lord and high class retainers. Total size of the ruin exceeds one kilometer long square, and becoming as a main base of traditional lord.
End of immortal clan
But Ouchi clan once lost before Shoni clan sent larger army to Seifukuji castle, and this time Iekane Ryuzoji just looked the situation. Isolated Sukemoto Shoni killed himself under the siege of Ouchi army in 1536, and Shoni clan experienced its fifth ruin.
However, the history of Shoni clan did not end at this time. Fuyuhisa Shoni (1510-1559), son of Sukemoto Shoni, ran to local lord and asked assistance to Iekane Ryuzoji. Under the support of Ryuzoji clan, Shoni clan recovered again, but fearing the power of Ryuzoji clan Fuyuhisa assassinated person of Ryuzoji clan except for Iekane and Takanobu.
Furthermore, Fuyuhisa allied with Otomo clan, the warlord of Bungo province (Oita prefecture), then expelled Takanobu Ryuzoji who succeeded Ryuzoji clan from his residence Muranaka castle (current Saga castle) to Chikugo province (south part of Fukuoka prefecture) in 1551. Takanobu Ryuzoji stayed at local lord Kamachi clan and seek chance of revenge, then in 1558 Takanobu raised his army and siege Seifukuji castle.
Fuyuhisa Shoni once rejected the attack of Takanobu, but next year Seifukuji castle faced fierce attack of Takanobu alike his nickname bear again. This time Fuyuhisa could not prevent the attack of Takanobu and killed himself at Seifukuji castle, then Shoni clan experienced their sixth and final ruin. Repeating down fall and recovery Shoni clan is said as zombies, but the winner of mixed martial arts between the animal and undead clan was the bear.
Afterward of castle
After the fall of Shoni clan, surviving relatives and former retainers still tried the recovery of Shoni clan, but this plan was prevented by Takanobu and did not realize. Takanobu Ryuzoji placed his younger brother Ietane Egami (?-1593), but Ietane moved to Hasuike castle (Saga prefecture) and Seifukuji castle was abolished at this time.
Today all building was lost but structures of the castle well remain at hilltop area, halfway ridge and hillside plateau. Castle ruin is just a continuation of flat area and clay wall, and not so appealing one. But long line of narrow terraces divided by deep dry moats or steep slopes quite resembles to the turbulent history of Shoni clan, which repeated down fall and revival many times and finally ended its history at Seifukuji castle.
30 minutes walk from JR West Fukushio-sen line Kamitode station. 30 minutes drive from Sanyo-do Expressway Fukuyama-Higashi interchange.