Kiyosu Castle: A Medieval Japanese Castle and Political Center
Site at a Glance
- Rating
- 4.1
- Popularity
- Medium
- Country
- Japan
- Primary era
- Modern
- External website
- Open
- Eras represented
- Early Modern, Modern
- Civilizations
- Japanese
- Site type
- Military
- Remains
- Castle
On this page10 sections
History
Kiyosu Castle is a flatland Japanese castle in Kiyosu, Japan, established around 1405 during the medieval period. Shiba Yoshishige, the shugo, or provincial military governor, of Owari, Tōtōmi, and Echizen, built it as a secondary fortress of Orizu Castle, the seat of Owari’s provincial government. Its position at the meeting point of the Kyoto–Kamakura highway and the Ise Kaidō, with connections to the Nakasendō, gave Kiyosu a strategically important role in regional administration and movement.
From Provincial Fortress to Political Center
Orizu Castle was destroyed by fire during an internal conflict within the Oda clan in 1476. Two years later, the provincial government moved to Kiyosu, transforming the castle into the political center of Owari. It became the principal stronghold of the Oda family branch whose shugodai, the local deputy or representative of a provincial governor, governed the four counties of lower Owari.
Oda Nobuhide, head of the Danjōchū branch of the Oda family, briefly lived at Kiyosu while serving as its bugyō, an appointed magistrate or administrative official. He later transferred his base to Furuwatari Castle, and Oda Nobutomo subsequently occupied Kiyosu. In 1554, Nobutomo ordered Shiba Yoshimune’s execution after Yoshimune disclosed an assassination plot to Oda Nobunaga. The following year, Nobunaga retook Kiyosu, forced Nobutomo to commit suicide, and moved there from Nagoya Castle.
Oda Nobunaga’s Residence
Nobunaga extensively rebuilt Kiyosu and made it his principal residence for about a decade. His control of the castle formed part of his consolidation of power in Owari during the Sengoku period, an era of warfare and political fragmentation when regional warlords competed for territory.
In 1557, Nobunaga’s younger brother, Oda Nobuyuki, was assassinated in the castle’s main keep. The episode belonged to the internal struggles through which Nobunaga strengthened his position. In 1560, Nobunaga left Kiyosu for the Battle of Okehazama, where he defeated Imagawa Yoshimoto despite being heavily outnumbered. Two years later, Nobunaga and Tokugawa Ieyasu concluded their alliance at Kiyosu. Known as the Kiyosu Alliance, the agreement joined the interests of two warlords whose campaigns later contributed to the political unification of Japan.
Nobunaga moved to Komakiyama Castle in 1563 while preparing for war with the Saitō clan of Mino. Kiyosu then continued as a garrison castle, retaining its military function after it ceased to be Nobunaga’s main residence.
Rebuilding and Toyotomi Rule
After Nobunaga’s death in the Honnōji Incident of 1582, leading figures met at Kiyosu to decide the succession. The meeting, known as the Kiyosu Conference, resulted in the castle passing to Nobunaga’s second son, Oda Nobukatsu, also called Oda Nobuo in some English accounts.
Nobukatsu undertook a major rebuilding in 1586. The work included two concentric moats, a large keep, a smaller keep, and a shoin, a formal reception or study building used in elite residential and administrative settings. The castle grounds were enlarged to approximately 1.6 kilometers from east to west and 2.8 kilometers from north to south. Liquefaction traces found beneath the castle town indicate that the Tenshō Earthquake of 1586 affected the area. Liquefaction occurs when water-saturated ground temporarily loses strength during an earthquake, leaving deformations and sand deposits. The evidence supports the interpretation that the earthquake may have helped prompt Nobukatsu’s rebuilding.
Nobukatsu later refused Toyotomi Hideyoshi’s order to exchange his domains after the Odawara Campaign. His lands were confiscated, and Kiyosu was incorporated into the territory of Toyotomi Hidetsugu. Fukushima Masanori, a prominent commander and daimyo who served Hideyoshi and later fought for the Eastern Army, became lord of the castle in 1595.
Relocation to Nagoya
During the Battle of Sekigahara in 1600, Kiyosu served as a rear base for the Eastern Army. After the battle, Fukushima Masanori was transferred to Aki Province, and Matsudaira Tadayoshi, Tokugawa Ieyasu’s fourth son, took possession of the castle. Tadayoshi died from illness caused by wounds received at Sekigahara in 1607. Ieyasu’s ninth son, Tokugawa Yoshinao, then entered Kiyosu and made it the seat of Kiyosu Domain.
Tokugawa Ieyasu ordered the seat of government to move from Kiyosu to Nagoya in 1609. Between 1610 and 1613, the castle town and its residents were transferred in the process called the Kiyosu-goe. Kiyosu Castle was dismantled for the construction of Nagoya Castle, and the completion of the new castle and the town’s relocation in 1613 marked Kiyosu’s abandonment as a castle.
Archaeology and Historical Memory
Only limited ruins remained by the Meiji period. Later development, together with the Tōkaidō Main Line and Tōkaidō Shinkansen, divided and erased much of the historic site. River works in 1988 led to the identification of liquefaction traces from the 1586 Tenshō Earthquake and the later Nōbi Earthquake. Excavations in 2011 uncovered remains and artifacts from a Heian-period settlement, the medieval castle town, and the later Kiyosu post-station settlement. Archaeological work also recovered part of a castle stone wall, which was reconstructed in a nearby park.
Kiyosu remains closely associated with Oda Nobunaga, the Battle of Okehazama, the Kiyosu Alliance, and the Kiyosu Conference. Physical elements connected with the castle survive beyond the archaeological site, including a turret at Nagoya Castle, a gate at Ryōfuku-ji, wall paintings at Sōken-ji, and roof ornaments at Sōfuku-ji. The relocated turret is an Important Cultural Property, the gate at Ryōfuku-ji is a municipal cultural property, and the surviving paintings at Sōken-ji are designated an Aichi Prefectural tangible cultural property.
Remains
Castle Layout and Surviving Groundworks
Kiyosu was a flatland castle organized around a large fortified complex with two rings of moats after the 1586 rebuilding. The expanded grounds covered approximately 1.6 kilometers east to west and 2.8 kilometers north to south. The original plan and overall appearance are not known, while part of the earthen rampart of the former main bailey survives as one of the principal remains at the historic site.
The Tōkaidō Main Line and Tōkaidō Shinkansen now cross the former castle grounds. Kiyosu Park occupies the area south of the railway, while Kiyosu Old Castle Ruins Park lies to the north. A section of stonework discovered during bank-protection works along the Gojo River has been reconstructed within the park. A bronze statue of Oda Nobunaga, erected in Kiyosu Park in 1936, also forms part of the modern presentation of the site.
Reconstructed Keep
The present keep was built in 1989 beside the historic site, within the Kiyosu Regional Cultural Plaza. It commemorated the centennial of the former town of Kiyosu. Because the original keep’s position and dimensions are unknown, the building is a reconstructed or simulated keep rather than an exact restoration.
Its richly decorated appearance evokes the Momoyama period, the late sixteenth-century era associated with powerful unifiers and increasingly elaborate castle architecture. The design was based partly on the keep of Inuyama Castle as a representative model of that period, rather than on a surviving plan of Kiyosu. The building contains a local history museum with displays of arms and armor.
Transferred Castle Features
Part of Kiyosu Castle’s former fabric survives at Nagoya Castle. The northwest corner turret of Nagoya Castle’s Ofukemaru Bailey incorporates materials from Kiyosu’s large or small keep and is known as the Kiyosu Turret. Its survival reflects the dismantling of Kiyosu during Nagoya’s construction and the reuse of castle materials in the successor stronghold.
A former castle gate was transferred to Ryōfuku-ji in Owariasahi. Gates traditionally associated with Kiyosu Castle are also preserved at Ganshō-ji and Chōkyū-ji in Nagoya. Portions of the castle’s decorated sliding-door paintings survive at Sōken-ji, while its original kinshachi, ornamental roof finials shaped like mythical carp or dolphin-like creatures, are preserved at Sōfuku-ji in Gifu City. Together, these turrets, gates, paintings, and roof ornaments extend the surviving physical record of Kiyosu beyond the present archaeological grounds.
