Sunpu Castle

Sunpu Castle, located in Aoi Ward, Shizuoka City, Shizuoka Prefecture, is a historic Japanese castle site now open to the public as Sunpu Castle Park, serving as a shared historical space for citizens and visitors alike. Historically, the castle was also known as Fuchu Castle, Suruga Fuchu Castle, and Shizuoka Castle. It was not only the political base for Tokugawa Ieyasu’s “Ōgosho Government” during his later years but also played a significant political role during the early Edo period and the Meiji Restoration.

The site’s history dates back to the Muromachi period, when the Imagawa clan built the “Imagawa Residence” as the political center of the Suruga region. However, it is uncertain whether the Imagawa Residence and the present Sunpu Castle site completely overlapped; archaeological evidence suggests that the Imagawa-period residence may have been located further to the west. In the Azuchi-Momoyama period, following the fall of the Takeda clan and the expansion of Tokugawa power, Ieyasu rebuilt Sunpu Castle in 1585 as a modern-style castle and moved in the following year, remaining there until he relocated to the Kanto region in 1590. Afterward, Toyotomi retainer Nakamura Kazuuji briefly took control, but following the Eastern Army’s victory at the Battle of Sekigahara, the castle returned to Tokugawa control.

After the establishment of the Edo shogunate, Ieyasu retired in 1606, passing the title of shogun to Tokugawa Hidetada, but continued to wield real power from Sunpu. He ordered an extensive reconstruction of the castle, creating a flatland fortress encircled by three concentric moats and building a massive tenshu (main keep) foundation. Historical records indicate that the tenshu base was among the largest in Japanese castle history, surrounded by multiple turrets and long yagura corridors, forming a grand defensive complex. The castle’s stone walls were built using “Izu Stone” from the Izu Peninsula, with historical documents noting the involvement of maritime transporters and merchants in the delivery and construction process.

After Ieyasu’s death, Sunpu briefly became the domain of his tenth son, Tokugawa Yorinobu, as the Sunpu Domain, but it soon reverted to direct shogunate control under a Sunpu Castle Magistrate until the end of the Edo period. Following the Meiji Restoration, the castle grounds were partially converted into a military camp, the inner moat was filled in, and the third bailey was gradually replaced by public facilities and schools as the city developed.

Today, the remains of Sunpu Castle primarily include the honmaru (main bailey) and ninomaru (second bailey), which have been developed into a public park hosting various events. While most of the outer moat has been filled in, portions of the inner moat remain, and the stone walls still bear traces of earthquake damage. In 1989, to commemorate Shizuoka City’s 100th anniversary, the Tatsumi Yagura (southeast turret) in the ninomaru was reconstructed, followed by the Higashi Gate and the Hitsujisaru Yagura, all rebuilt using traditional techniques. These structures now serve both educational and tourism purposes and have been recognized with the “Handmade Hometown Award.” In recent years, archaeological excavations of the tenshu base have continued, providing further insights into the castle’s structure and historical evolution.