Shinpu Castle is located on a mountain with steep sides overlooking the Kamanashi River to the west of Kōfu, where Takeda Shingen's Tsutsujigasaki Castle was located. Following Shingen's death, his son and successor, Takeda Katsuyori initially successfully expanded his territory into eastern Mino Province; however, suffered a major defeat against Oda Nobunaga's matchlock-armed forces at the Battle of Nagashino, losing four of his top generals. Following this defeat, the Takeda found themselves surrounded by increasing aggressive neighbors, including the Oda, the Tokugawa clan, the Uesugi clan and the Odawara Hōjō clan. Katsuyori felt that a mountain-top castle located near the center of his domains would be easier to defend, and thus relocated from Tsutsujigasaki Castle in 1581.
Structure
The castle is located on a hill and its defenses enclose an area 500 meters long by 200 meters wide in a north-south orientation. The Inner bailey was a square enclosure at the top of the hill, and connects to the main gate, which was located to the west, via a second bailey. The layout thus somewhat resembles the layout of Tsutsujigasaki Castle. South of the central area was a large third bailey, which was approximately 100 meters long and divided into two kuruwa by a clay wall. The main gate of the castle was also fortified by a half-circular fortification with a dry moat. The northern side of the castle was also fortified by two protections, which extended into a water moat.
History
In early 1582, before the castle or its jōkamachi were even complete, an Oda-Tokugawa alliance invaded the Takeda holdings in Shinano Province. Takatō Castle fell after only one day, and many Takeda retainers defected or simply ran away. The Oda-Tokugawa alliance advanced into Kai Province, and laid siege to Shinpu Castle at Battle of Tenmokuzan. Takeda Katsuyori was unable to hold the castle with his remaining 300-400 men, so on March 3, 1582 he set fire to Shinpu Castle and fled into the mountains, attempting to reach another Takeda stronghold, Iwadono Castle, held by Oyamada Nobushige, an old Takeda retainer. Katsuyori was denied entry by Oyamada, and committed suicide while the last remnant of his army held off their pursuers. The castle was used briefly by Tokugawa Ieyasu during mopping up operations against the remnants of the Takeda forces, and to hold the province against the Odawara Hōjō, and was allowed to fall completely into ruins afterwards. Today, no structures remain of the castle except for the remnants of some dry moats and earthenworks. The site of the former Inner bailey of the castle is now occupied by a Shinto shrine. The castle was listed as one of the Continued Top 100 Japanese Castles in 2017.
