Konosumiyama Castle

Overview

Konosumiyama Castle (此隅山城, Konosumiyama-jō) was a Japanese castle of the Muromachi period (1336–1573), built in 1372 and abandoned in 1569. It stood on a hill in the Izushi district of what is now the city of Toyooka, in Hyōgo Prefecture, in the northern part of the Kansai region. The castle was a mountain stronghold of the type the Japanese call yamajiro (山城, やまじろ), a fortification built along ridgelines and hilltops rather than on the flat plain. Its ruins, together with those of the nearby Arikoyama Castle, have been protected as a National Historic Site since 1934 under the designation "Yamana clan castle ruins" (山名氏城跡, Yamana-shi shiro ato).

The castle's near-two-century lifespan spans the whole arc of Muromachi power politics: it was founded in the first decades of Ashikaga shogunate rule and abandoned in the generation of Oda Nobunaga, when the old order of regional lords was being dismantled.

History

Konosumiyama Castle was founded in 1372, in the first year of the Bunchū era (文中, ぶんちゅう) — an era name that was in fact used by the rival Southern Court, a detail that places the castle's foundation squarely in the middle of the Northern and Southern Courts conflict that split Japan in the fourteenth century. The castle belonged to the Yamana clan (山名氏, Yamana-shi), one of the great warrior houses of the Muromachi period, whose power base lay in the San'in region along the Japan Sea coast. The Yamana were prominent enough to supply shugo (守護, しゅご), provincial military governors, across a wide stretch of western Japan, and at their height were among the most powerful families in the country.

The castle's position in the Izushi basin gave the Yamana a defensible stronghold inland from the coast, controlling routes through the mountains of what is now northern Hyōgo Prefecture. Konosumiyama was one of a pair of Yamana castles in the area; the other, Arikoyama Castle, stands nearby and shares the National Historic Site designation.

The castle was abandoned in 1569. By that date the Yamana clan's power had been in long decline, and the castle's end belongs to the wider process by which the scattered mountain strongholds of the Muromachi and Sengoku periods were superseded by the consolidated castle towns of the late sixteenth century. The site was never rebuilt as a major fortification.

What Stands There Today

The castle site today is an archaeological and landscape remnant rather than a standing castle. No keep, gate or building survives; what remains are the earthworks of a yamajiro — the shaped ridges, terraced enclosures and cut defences that define a mountain castle. The ruins are preserved within the National Historic Site designation granted in 1934, which covers both Konosumiyama Castle and Arikoyama Castle jointly as the "Yamana clan castle ruins". The site lies in the Izushi neighbourhood of Toyooka, a district known today for its preserved castle town of a later date, centred on Izushi Castle.

The Name in Japanese

The castle's name in Japanese is 此隅山城, read in kana as このすみやまじょう, and in romaji as Konosumiyama-jō. It is built from four characters, read as follows:

• 此 — read kono here. This is the native Japanese demonstrative meaning "this". In ordinary modern Japanese it is usually written in kana rather than kanji, but in names and older texts the character appears regularly.
• 隅 — read sumi. It means "corner", "nook" or "recess" — the sense of an angle or an out-of-the-way spot. The same character appears in the Tokyo place name Sumida (隅田) and in the word sumi (隅, すみ) for a corner.
• 山 — read yama. The standard character for "mountain", one of the most common elements in Japanese place names and castle names.
• 城 — read jō. The character for "castle". In compound names it is normally read jō, as here; on its own it can be read shiro.

So the name as a whole means something like "this-corner mountain castle" — a castle on the mountain at this corner or recess of the landscape. The reading jō rather than shiro is the standard one when 城 closes a castle name, and it is the reading to use when saying the name aloud. Note that the final -jō is not a separate word: 此隅山城 is a single compound name.

Visiting and Context

The castle ruins sit in the Izushi area of Toyooka, in northern Hyōgo Prefecture. The nearest major transport hub is Toyooka, and the Izushi district is reached from there; the castle site is a hilltop earthwork rather than a developed tourist attraction, so visitors should expect walking terrain rather than reconstructed buildings. The site's inclusion in the 1934 National Historic Site designation means it is a protected monument.

For readers of Japanese, the castle's name is a useful study case: it combines a native Japanese demonstrative (此), a common landscape noun (隅), the ubiquitous place-name element 山, and the castle suffix 城 read jō. The era name Bunchū (文中) that dates its foundation is likewise worth knowing — it belongs to the Southern Court line of era names, a reminder that in the fourteenth century Japan had two competing courts and two competing calendars. Konosumiyama Castle's 1372 foundation and 1569 abandonment bracket a period in which the Yamana clan rose, held, and lost its regional dominance, and the earthworks on the hill above Izushi are what remains of that story.