Kiyosu Castle

Overview

Kiyosu Castle (清洲城, Kiyosu-jō) is a Japanese castle in Kiyosu, a city in western Aichi Prefecture. Its site lies on the flat Nōbi Plain, at coordinates roughly 35.22° north and 136.84° east, in country that was for centuries the crossroads of central Japan. The castle is chiefly remembered for its association with the rise to power of the Sengoku-period warlord Oda Nobunaga (織田信長, 1534–1582).

The castle's foundation is dated to 1394, the first year of the Ōei era (応永) in the Muromachi period (1336–1573). In the centuries that followed, Kiyosu became the seat of the Kiyosu Domain (清洲藩, Kiyosu-han), the administrative territory centred on the castle.

History

Kiyosu Castle was founded in 1394, the opening year of the Ōei era, during the Muromachi period. That dating places its origins in the decades when the Ashikaga shogunate governed from Kyoto and castle-building across the provinces was still on a modest scale.

The castle's historical importance, however, comes from the Sengoku period (戦国時代, sengoku jidai, "Warring States period"), the long era of civil war that ran from the fifteenth into the late sixteenth century. Kiyosu was the stronghold from which Oda Nobunaga extended his power over the surrounding provinces. Nobunaga would go on to become one of the three great unifiers of Japan, and Kiyosu stands at the beginning of that career.

After Nobunaga's time the castle gave its name to the Kiyosu Domain, the feudal territory administered from it. The castle's fortunes followed those of the domain through the early modern centuries.

What Stands There Today

The castle visible at Kiyosu today is a partial reconstruction. It was built in 1989 to mark the centennial of the modern city of Kiyosu. The present structure therefore reproduces the castle's form rather than preserving original fabric; it is a modern monument to the site's history, not a surviving medieval or early modern keep.

The Name in Japanese

The castle's name is written 清洲城. In kana it is read きよすじょう, and in romaji, Kiyosu-jō. The final element, 城, is the standard kanji for "castle"; on its own it is read shiro, but in compound names such as this one it takes the Sino-Japanese reading jō.

Breaking the name down character by character:

• 清 — read kiyo in this word. It means "clear", "pure", or "clean". It is the same character found in such names as Kiyomizu (清水, "clear water").
• 洲 — read su in this word. It means "sandbank", "riverbank", or "continent" — a flat, raised piece of land in or beside water. The combination 清洲 thus suggests a clear, clean sandbank or riverbank, an apt image for a castle on the low, watery Nōbi Plain.
• 城 — read jō in this word. It means "castle" or "fortress".

A note on the spelling: the castle's name was historically also written 清須城, using 須 in place of 洲. Both spellings refer to the same place, and the modern city and castle are written with 洲. Learners who meet the older form in historical texts should not be thrown by the swap — the reading Kiyosu is unchanged.

Visiting and Context

Kiyosu lies in western Aichi Prefecture, within easy reach of Nagoya, the prefectural capital and one of Japan's largest cities. The castle's position on the Nōbi Plain puts it in the heart of the region where the drama of the Sengoku period was played out, and it makes a natural stop for travellers following the careers of the three unifiers — Oda Nobunaga, Toyotomi Hideyoshi and Tokugawa Ieyasu — whose homelands and strongholds cluster in this part of central Japan.

For students of Japanese, the site offers a compact lesson in the language of castles. The word 城 (shiro / jō) recurs in castle names across the country, and the alternation between the native reading shiro and the Sino-Japanese reading jō is a pattern worth internalising. The name 清洲 itself, with its image of clear water and a sandbank, is a reminder that Japanese place names usually describe the landscape they sit in — here, the rivers and flats of the Nōbi Plain.