Yamanaka Castle

Overview

Yamanaka Castle (山中城, Yamanaka-jō) was a Japanese castle in Tagata District, Izu Province, on the site of what is now eastern Mishima in Shizuoka Prefecture. It was built by the Odawara Hōjō clan, the warrior house that dominated the Kantō region during the Sengoku period — the "Warring States" era of near-constant military conflict that ran from the mid-fifteenth into the late sixteenth century.

It was a yamajiro (山城, yamajiro), a mountain castle: rather than a flatland fortress with a stone keep, it was laid out along ridges and slopes, using earthworks, ditches and steep ground as its principal defences. Construction is dated to 1469, the first year of the Bunmei era (文明, Bunmei), which places its foundation in the Muromachi period (1336–1573). The castle's active life ended in 1590, when it was destroyed in the Siege of Odawara, the campaign in which Toyotomi Hideyoshi broke the Hōjō clan's power.

The site is listed among the 100 Fine Castles of Japan (日本100名城, Nihon 100 Meijō), a designation maintained by the Japanese Castle Foundation. The ruins have been protected by the central government as a National Historic Site since 1988.

History

The Odawara Hōjō were based at Odawara in Sagami Province, and by the middle of the sixteenth century they controlled most of the Kantō plain as well as the Izu Peninsula. Izu mattered to them for a specific reason: it was the peninsula that jutted south into the sea toward the sea routes running along the Pacific coast, and it guarded the western approach to their heartland. Yamanaka Castle sat at the neck of that approach, in the Tagata District of Izu Province, positioned to watch the roads and passes that an army marching from the west would have to use.

The castle's date of foundation, 1469, falls in the Bunmei era, early in the long period of provincial warfare out of which the Hōjō themselves emerged. Over the following century it was developed into a substantial mountain stronghold, its slopes cut into a series of terraces and its approaches blocked by dry moats and earthen ramparts — the standard vocabulary of Sengoku-era mountain defence, which relied on massed earthwork rather than masonry.

Its end came in 1590. Toyotomi Hideyoshi, having unified most of Japan, moved against the Hōjō in the Siege of Odawara. Yamanaka Castle was one of the Hōjō outworks in the path of the attacking armies, and it was destroyed during that campaign. With the fall of Odawara, the Hōjō domain was extinguished and the castle was never rebuilt.

What Stands There Today

What survives at Yamanaka is the earthwork itself. The terraces, the dry moats (karabori, 空堀, dry ditches cut into the hillside) and the raised embankments remain legible in the ground, which is characteristic of yamajiro sites: because the defences were dug and piled rather than built up in stone, they erode into the landscape rather than disappearing from it entirely. There is no surviving keep or main hall.

The ruins were designated a National Historic Site in 1988, which placed them under the protection of the central government and made their preservation a matter of national rather than local administration. The site is also included in the 100 Fine Castles of Japan, a list that directs attention to castles of historical importance regardless of whether any buildings survive.

The Name in Japanese

The name is written 山中城 and read やまなかじょう in kana. In romanised form it is Yamanaka-jō; the macron over the final o marks a long vowel, so the last syllable is held roughly twice as long as a short one.

The name breaks into three kanji:

• 山 — read yama here. It means "mountain". This is one of the most recognisable characters in Japanese and appears in hundreds of place names and surnames.
• 中 — read naka here. It means "middle", "inside" or "among". Combined with the first character, 山中 (Yamanaka) means "in the mountains" or "middle of the mountain" — and it is also a common Japanese surname.
• 城 — read jō here. It means "castle". This is the character that tells the reader the word is a fortress name.

The reading of 城 is where learners most often stumble. Standing alone, the character is usually read shiro, and that is the everyday Japanese word for a castle. In compound names it is normally read jō, and when it follows a word ending in a vowel or n, the two sounds run together: Yamanaka + jō becomes Yamanaka-jō. The same pattern gives Osaka-jō, Himeji-jō and Odawara-jō. The word 山城 can also be read yamashiro, and in that reading it is the general term for a mountain castle — which is exactly what Yamanaka was. The name and the category are, in effect, the same two characters.

Visiting and Context

Yamanaka Castle is in eastern Mishima, in Shizuoka Prefecture, at coordinates roughly 35.16° north, 138.99° east. Mishima itself is a well-known stop on the Tōkaidō, the historic highway linking Edo and Kyoto, and it sits at the foot of Mount Fuji — the castle's ridges look out toward the mountain and across to the Izu Peninsula.

For readers of Japanese, the site is a useful study in vocabulary that recurs constantly in historical texts. Yamajiro (山城) describes the mountain-fortress type; karabori (空堀) describes the dry moat; kuruwa (曲輪) describes the flattened, defended terraces into which such a mountain was cut. None of these words require a stone keep to make sense, which is why a site like Yamanaka can be almost empty of buildings and still be a castle in the full historical sense.

Its place in the wider story is fixed by two dates. It was founded in 1469, at the opening of the Bunmei era, and it was destroyed in 1590 in the Siege of Odawara — the campaign that ended Hōjō rule and closed the Sengoku period's long chapter of regional warfare. The castle therefore spans almost exactly the century of Japanese history that its earthworks were designed for.