Ishihamajō was a medieval fortification site situated on the right bank of the Sumida River. The location was an important ferry-crossing point. It is not known when Ishihamajō was first built, but from the Kamakura period the Edo Clan used the castle as its main base. In 1352, during the Musashino War, when Nitta Yoshisada pushed back Ashikaga Takauji, it is thought that Takauji retreated to Ishihamajō and used it as his base. The Musashi-Heiiki, a confederation of local clans supporting Ashikaga Takauji, repelled Nitta Yoshisada at the castle (but other castles are theorised to have been the site of this battle too).
Ishihamajō further saw conflict during the Kyōtoku no Ran, a period of civil strife in Kantō lasting from 1455 to 1483. In the conflict Chiba Sanetane was pushed out of Shimōsa Province. Allying with the Ōgitani-Uesugi Clan, he made Ishihamajō his new headquarters. After the fall of the Ōgitani-Uesugi, the Chiba Clan became vassals of the Later Hōjō. In 1590 the Hōjō were defeated in Toyotomi Hideyoshi’s conquest of Kantō, and Ishihamajō was either abandoned or destroyed at that time.
Ishihamajō is a medieval castle of which nothing remains. The site is known principally from historical documents. The site today, the location of which is deduced rather than unearthed, is that of Ishihama Shrine and Ishihama Castle Park (the exact location of this site is disputed as there are different theories, but Tōkyō Metropolitan authorities list it as a buried cultural property just north of Ishihama-jinja). Ishihama Castle Park is basically a small, local park with some sports cages and benches. I’ve never been to a park named for a castle with so little castle to see. The shrine is nice, and it does have some modern mock-up ishigaki, which is the closest one gets to the feeling of a castle here. Other castle sites in Tōkyō are now things like office blocks, so Ishihamajō is lucky it got a park! It is considered of some historical importance and also has a Japanese language Wikipedia article.
|Edo Clan; Chiba Sanetane
|Kamakura Period; Muromachi Period
|Pre Edo Period
|Minami-Senju Station; 15 minute walk
|24/7 free; park / shrine
|35° 43' 42.56" N, 139° 48' 29.59" E
|Added to Jcastle
|Admin Year Visited
|Friends of JCastle