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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