Just prior to the Battle of Sekigahara, the western forces under Ishida Mitsunari encroached upon eastern territories, making it as far as Ogaki Castle, where due to poor planning and poor intelligence, the Western armies found themselves trapped. The Eastern forces had quickly set up camp on Akasaka, a large mountain west of Ogaki and located between Ogaki and the Western troops’ only means of escape, the narrow gap in the mountains separating East and West Japan, known as Sekigahara.
While waiting for the advent of Tokugawa Ieyasu, two of his most able generals, Honda Tadakatsu and Ii Naomasa chose a well-positioned low mountain known as Okayama, and built a jinjiro, a fortified command post befitting Ieyasu’s status and in preparation for the upcoming battle, which the generals of East and West all expected to take place on the plains between Ogaki and Tarui.
Okayama Jinjiro was surrounded by wide, deep karabori (dry moats) and dorui (earthen embankments) topped with spiked log and bamboo fencing. There were three main gates, all kuichi koguchi, (meaning the entrances were of overlapping construction, preventing direct access) located in the northwest, northeast and south. The northwestern main entrance was a masugata configuration. These masugata, or death box, configurations were the strongest type of gate defense stopping, trapping and containing enemy infiltrators attempting to enter. The Okayama Jinjiro contained three main kuruwa (baileys) all with protective dorui around the outer edges.
There are various types of castle, Yamajiro are mountain castles, Hirajiro are plains castles, Hirayamajiro make use of both a hill or small mountain and the flat lands around its base. There are also Jinya, small castle like defensive positions held by low-ranking Daimyo and high ranked Hatamoto, and there are Jinjiro, literally “fortified battle camps”. One of the largest Jinjiro was Okayama Jinjiro in Ogaki City, Gifu Prefecture.
Unfortunately, the main kuruwa was used by Ogaki City to situate a mains water supply tank, while the other kuruwa baileys are used as graveyards and farmland. Some of the moats and dorui, as well as some sections of kuruwa can still be seen to this day, although the aforementioned water tanks and graveyards have changed the site and damaged historical earthworks.
Profile by Chris Glenn (edited by ART).
|English Name||Okayama Jinjiro|
|Founder||Honda Tadakatsu and Ii Naomasa|
|Castle Condition||Ruins only|
|Historical Period||Pre Edo Period|
|Artifacts||Hori, Dorui, Kuruwa|
|Access||Mino-Akasaka Station on the Mino-Akasaka Branch Line; 10 minute walk|
|Visitor Information||24/7; free; mountain|
|Location||Ogaki, Gifu Prefecture|
|Coordinates||35° 23' 3.44" N, 136° 34' 48.22" E|
|Added to Jcastle||2022|
|Admin Year Visited||Viewer Contributed|