Asuke Castle, situated in Aichi Prefecture, may have been modest in size, but it played a pivotal role in numerous battles. It stands as one of Japan’s earliest and finest examples of a meticulously reconstructed Yamashiro-type castle from the Sengoku period.
Perched atop a 301-meter high hill named Mt. Mayumi in western Mikawa (now eastern Aichi Prefecture), Asuke Castle was originally founded in the 15th century by the Suzuki Clan. In 1525, Matsudaira Kiyoyasu, the grandfather of Tokugawa Ieyasu, launched an assault on Asuke. He not only captured the castle but also assimilated the Suzuki samurai into the Matsudaira clan.
However, in 1554, the Suzuki clan severed ties with the Matsudaira when the formidable Imagawa clan attacked. Overwhelmed, the Suzuki surrendered to the invaders. Two decades later, in 1564, Tokugawa Ieyasu, leading a 3,000-strong army, reclaimed Asuke, reinstating the Suzuki clan as vassals.
The castle saw further turmoil when Takeda Shingen seized it with 25,000 samurai in 1571. Nonetheless, in 1575, Matsudaira Nobuyasu, Ieyasu’s eldest son, besieged and defeated the Takeda forces, restoring Asuke to Tokugawa control. Eventually, Asuke was deserted in 1590 when Ieyasu accepted Toyotomi Hideyoshi’s offer to govern the Kanto districts, prompting him to relocate his headquarters to Edo (present-day Tokyo).
Given its repeated sieges, Asuke Castle held strategic significance, guarding the vital Ina Highway, also known as the “Salt Route,” which connected Owari Mikawa (eastern Aichi) with Shinano (Nagano Prefecture).
Asuke Castle, perched on a steep, cliff-like hill, was encircled by rudimentary log fences instead of stone walls. Although its unique defensive features like the Sakamogi trees are no longer present, nearly all aspects of Asuke Castle have been faithfully reconstructed. From its simple watchtowers and basic living quarters to its stables and defenses, every detail reflects the authenticity of the original structure.
The Minami-no-Maru, the main southern bailey, resembles an open fan and was originally occupied by kitchens and living quarters, as evidenced by unearthed artifacts. It features a nagaya-type dwelling with an irori fireplace inside and a simple kitchen outside. A wooden bridge leads to a lookout tower, offering views of Kessoku Castle’s ruins, a satellite fortress within the regional communication network.
Atop the central Honmaru stands the Taka-Yagura, a two-story tower with wooden shingles for roofing and black protective boarding on the lower two-thirds of both floors. Adjacent to it is a narrow nagaya housing, built using mud-faced walls and wood panels, serving as a defensive structure.
The samurai maintained provisions of weapons, food, and water within the castle, with the Nagaya featuring a dirt floor containing salt, a vital resource during sieges. The castle walls, constructed using the wattle and daub technique, could be chipped open during sieges to access dried taro potato stalks for emergency use.
Below the castle lies the town of Asuke, which thrived as a post station along the Chumakaido route for transporting salt and other goods. Today, remnants of its past, including houses with blackboarded walls and warehouses with white earthen walls, adorn the townscape, evoking its defensive heritage.
See also
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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.
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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).
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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.
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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.
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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.
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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.
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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.
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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.
