Japan Castle Explorer: Ishigakiyama Castle -Master of sieging castle-

Ishigakiyama Castle

-Master of sieging castle-

Overview

Name: Ishigakiyama castle (Ishigakiyama-jo)
Alias: Ichiya-jo (One-night built castle)
Place: Hayakawa Odawara city, Kanagawa

Location: 35.23532418872244, 139.12859706746724
Type: Hill castle
Built: 1590
Remaining remnants: Stone walls and dry moats
Title: Designated national historical site, 100 more famous Japanese castles

Brief History

Ishigakiyama castle (石垣山城) is located on the hill named Kasagakeyama at three kilometer west from Odawara Castle which was the main base of Hojo clan. From the hill, entire part of Odawara castle is well seen.

This castle was built by ruler Hideyoshi Toyotomi (1537-1598), as a camp for sieging Odawara castle on his Odawara campaign in 1590 against Hojyo clan. But this castle was not a temporary disposable one, but a genuine fortress equipped with main tower and covered with stone walls.

Hideyoshi Toyotomi, a master of sieging castle

Hideyoshi Toyotomi was a master of sieging castle, promoted and seized the hegemony using this skill effectively. In the latter half of Sengoku era, the attack to castles became harder and harder, because more organized warlords built secure defence facilities in their castles, and matchlock gun had rapidly spread. If defense side had sufficient soldiers with guns and supplies, as long as they kept will of resisting, attack side had to pay for tremendous damage but even if so it was not clear to occupy or not.

Facing this situation, Hideyoshi grow three necessary skills for sieging castle. The first skill was invitation of betrayal. It has been common method in sieging castle to let the commander or general betray, but based on above situation, to let enemy open the castle during siege was the method with least damage. As an upstart person originally had no power and authority, Hideyoshi was very skillful at charming people.

Secondary Hideyoshi brought large constructions for siege. Originally Nobunaga Oda (1534-1582), his master build a long wall to shut the communication when he attacked Azai clan around 1570, and Hideyoshi refined this and brought to sieging. When he attacked Miki castle (Hyogo prefecture) in 1578, taking three years he completely surrounded Miki castle by walls and totally shut down the supply line, and the commander of Miki castle finally had to open the castle due to the lack of supplies.

Hideyoshi used same method at the sieging of Tottori castle (Tottori prefecture) in 1580. This time he bought up foods in the castle area in advance and built a encircling castle at a stretch, then enemy side only stand three months.

Hideyoshi also brought flood attack in sieging. When he attacked Takamatsu castle (Okayama prefecture) in 1582, the castle was surrounded by marshes and hard to attack. Hideyoshi and his military staff Yoshitaka Kuroda (1546-1604) took advantage of this terrain, constructed a bank to dam a river and pour water into the castle area.

Suffered from submergence, the commander had to open the castle in one month. Hideyoshi also used this tactics during his attack to local lords and religious groups in Kii country (Wakayama prefecture) in 1586, and his general Mitsunari Ishida (1560-1600) also did when he attacked Oshi castle (Saitama prefecture) during Odawara campaign.

Finally, Hideyoshi was good at astonishing enemy, to let hem lose their willing of fight. When he fought with Akiduki clan in Kyusu campaign, he captured Ganjyaku castle, which was know hard to attack, in only one day. Further, Hideyoshi repaired buildings of this castle in only one day (probably fake building), then Akizuki clan gave up their resistance.

On and after Odawara campaign

Odawara campaign is the final battle of uniting Japan, and also a compilation of his sieging castle. Firstly Hideyoshi induced Norihide Matsuda, an important retainer of Hojyo clan, to betray their clan. Secondly, Hideyoshi encircled whole Odawara castle with his numerous army and ships of naval lords, and as a final closure, he built Ishigakiyama castle, a permanent castle used new technology.

Hideyoshi built this castle in very short time behind the woods, and suddenly showed the complete castle to Hojo side by cutting down trees as if the castle was built in a day. He also hold a tea party with his generals and wives in this castle, to show off his dominant position to Hojo side. Now that things have come to this pass, Hojo clan recognized it was impossible to resist more, and surrendered.

After the campaign this castle was abolished, but the site had been kept during Edo era. The side was damaged by Great Kanto earthquake in 1923, but there still remain ruins of stone walls with magnificent impression.