Hasedō Castle

Hasedō Castle was a medieval mountain castle in the Hasedō district of Yamagata City, Yamagata Prefecture. Because of the shape of the hill it was also called Kamegajō ("Turtle Castle"). For the Mogami clan of Yamagata Castle it was an important branch fortress guarding against the Date clan to the south. In 1600 it became the front line against the Uesugi army under Naoe Kanetsugu, in what is known as the Battle of Hasedō.

Founding and first record

The castle was built by the Mogami clan in the early 16th century. Its first appearance in the records is in 1514, when Date Tanemune is said to have taken it. After this fighting the Mogami are said to have made peace on unfavorable terms and fell under Date dominance.

Structure

It stood on a summit 229 m above sea level, laid out as a row of terraced enclosures. No keep was built. Enclosures, earthen ramparts, and moats survive.

The Keichō Dewa campaign

In 1600, at about the same time as Sekigahara, the army of Naoe Kanetsugu, acting for Uesugi Kagekatsu of the western side, invaded the territory of Mogami Yoshiaki, who sided with the east. Hasedō Castle became a target as a stepping stone toward Yamagata Castle. The castellan Shimura Mitsuyasu held it with about 1,000 men. The muddy rice fields at the foot of the hill are said to have helped the defense and slowed the Uesugi advance. When news came that Ishida Mitsunari and the western army had lost at Sekigahara, the Uesugi army was forced to withdraw.

After the war and demolition

After the war the castle was given to Saka Mitsuhide and then passed to his son Saka Mitsushige. After the Mogami disturbance of 1622, when Mogami Yoshitoshi was dispossessed, the castle was confiscated and razed.

Today

The whole hill is now a castle-ruin park called Jōyama, and the summit offers views of Yamagata City and the Zaō mountains. Nearby sites include Hasedō Kannon, Seigen-ji, and the Takiyama-ji ruins.