Kiyosu Castle was initially constructed around 1405 by Shiba Yoshishige, the Governor of Owari, serving as a major strategic defense and later as the seat of power for the Owari region (now Aichi Prefecture). One branch of the Oda clan, administrators of Owari, took control of southern Owari and Kiyosu Castle from 1476, while the other branch was based in Iwakura Castle, overseeing northern Owari.
Kiyosu Castle was the launch point for many significant samurai battles during the turbulent Sengoku, or Warring States Period (1450-1615), including the battles of Okehazama (1560), Anegawa (1570), Nagashino (1575), and Sekigahara (1600).
In 1555, after the death of his father, Oda Nobunaga enlisted the help of his uncle, Oda Nobumitsu, to attack and kill Oda Nobutomo, the clan leader at Kiyosu Castle. Nobunaga subsequently relocated from Nagoya Castle to Kiyosu. Two years later, he discovered a plot by his younger brother, Nobuyuki, to overthrow him. Feigning illness, Nobunaga drew Nobuyuki close and assassinated him within Kiyosu Castle, thereby eliminating opposition and ensuring clan stability.
Kiyosu remained Nobunaga’s base for many years, during which time the city flourished due to his economic reforms and enhanced security. The castle grounds once spanned 1.6 kilometers east-west and 2.8 kilometers north-south, featuring an outer, central, and inner moat system.
On July 16, 1582, just weeks after Nobunaga’s death at Honno-ji Temple in Kyoto, an important meeting regarding the Oda clan’s succession, known as the Kiyosu Conference, was held at Kiyosu Castle. Top Oda retainers, including Shibata Katsuie, Toyotomi Hideyoshi, Niwa Nagahide, and Ikeda Tsuneoki, gathered to decide on Nobunaga’s successor. With Nobunaga’s designated heir, Nobutada, having died at Nijo Castle, the succession was contested between Toyotomi Hideyoshi, who supported Oda Samboshi (Nobunaga’s infant grandson), and Shibata Katsuie, who backed Nobunaga’s third son, Nobutaka. The conference ended without resolution, leading to escalating tensions between Hideyoshi and Katsuie, culminating in the Battle of Shizugatake. Ultimately, Hideyoshi triumphed, leading to Katsuie’s defeat and suicide, and Hideyoshi's eventual domination of Japan.
Following the Battle of Sekigahara in 1600, Kiyosu Castle saw various masters. It was reconstructed in concrete in 1989 across a small river from its original location. The actual site of the keep now features the "Kiyosu Furusato no Yakata," a small rest area and souvenir stall. Surprisingly, the JR train lines and Bullet Train lines run directly through the old castle site. The southern half of Kiyosu Castle is now a park with statues of Oda Nobunaga in full armor and his wife, Princess No-Hime.
The current reconstructed Kiyosu Castle serves as a symbol of Kiyosu City and houses a well-planned museum featuring fascinating displays and artifacts related to the castle’s history and its role in the Period of Warring States.
See also
-
Kaminoyama Castle
Kamino-yama Castle stood at the center of an important logistics hub, in the middle of the Yonezawa Plain, which served as the gateway to the western part of the Tohoku region. Roads connecting the Aizu, Fukushima, and Yamagata areas intersected here.
-
Imabari Castle
Tōdō Takatora (1556–1630) served at different times as a vassal of several famous clans—Azai, Oda, Toyotomi, and Tokugawa. He took part in the Battle of Anegawa (1570), the Battle of Shizugatake (1583), the invasions of Kyushu and Korea, the Sekigahara campaign (1600), and the Siege of Osaka (1614–1615).
-
Iwakuni Castle
Kikkawa Hiroie (1561–1625) was the grandson of the famous daimyo Mori Motonari and a vassal of the Mori clan. Under Mori Terumoto, he fought in both Korean campaigns and took part in the defense of Ulsan Castle. During the Battle of Sekigahara, Hiroie stood with his 3,000-man force on the side of the Western Coalition; however, even before the battle began, he sent Tokugawa Ieyasu a secret message stating that he did not intend to fight Tokugawa’s troops. As a result of his inaction, 15,000 soldiers under Mori Hidemoto were also unable to enter the battle, since Hiroie blocked their path.
-
Gujo Hachiman Castle
Gujo Hachiman Castle is located on 350-meter Mount Hachiman, near the confluence of the Yoshidagawa and Kodaragava rivers, and not far from the Nagaragawa River. During the Sengoku period, this area was of great strategic importance: it stood at a key crossroads of routes connecting Mino Province in the south with the Sea of Japan in the north, and Hida Province in the east with Echizen Province in the west.
-
Amagasaki Castle
The founding year of Amagasaki Castle is traditionally considered to be 1617, when Toda Ujikané built his castle here, making it the administrative center of the Amagasaki Domain. However, as early as the Sengoku period, a fortress built by the Hosokawa clan already stood on this site. After the fall of Itami Castle in 1579, Araki Murashige—formerly a vassal of Oda Nobunaga who had rebelled against him—fled to this earlier castle.
-
Hiroshima Castle
Mōri Terumoto (1553–1625) was the grandson and rightful heir of the renowned Mōri Motonari. When Terumoto became the head of the Mōri clan in 1571, he inherited vast territories covering a large part of the San’in and San’yō regions in western Honshū. In addition, the Mōri clan possessed the largest and most technologically advanced naval fleet of its time.
-
Fukuyama Castle
After the defeat of Toyotomi Hideyori’s supporters in the Osaka Campaigns of 1614–1615, many clans in Japan still remained not fully loyal to the Tokugawa shogunate, especially in the western Chūgoku region. Mizuno Katsunari (1564–1651), a cousin of Tokugawa Ieyasu, became the first of the Tokugawa house’s close retainers, the so-called fudai daimyō, to be relocated to this strategically important area.
-
Tiba Castle
The founder of the Chiba clan is considered to be Chiba Tsunesige (1083–1180), who in 1126 moved his residence to the Inohana area and built a strongly fortified stronghold there. Although Tsunesige himself came from the Taira clan, the Chiba clan later supported Minamoto no Yoritomo, the future founder of the first shogunate.
