Kameyama Castle

Overview

Kameyama Castle (亀山城, Kameyama-jō) stands in the city of Kameoka in Kyoto Prefecture, on the northwestern approach to the old imperial capital. It was founded in 1578, in the sixth year of the Tenshō era (天正, てんしょう), during the Azuchi–Momoyama period (安土桃山時代, 1573–1603). For close to three centuries it guarded the road corridor that led into Kyoto from the north-west, and it is remembered above all as the castle from which Akechi Mitsuhide set out in 1582 to attack Oda Nobunaga at Honnō-ji.

History

The castle was built by Akechi Mitsuhide (明智光秀, あけち みつひで), a senior vassal of Oda Nobunaga (織田信長, おだ のぶなが). Mitsuhide needed a forward base for the conquest of the Tanba region (丹波国, たんばのくに), the province in which Kameoka lies, and Kameyama Castle served that purpose from 1578. The site controlled the routes running north-west out of Kyoto, which gave it strategic value beyond the Tanba campaign itself.

The castle's place in national history comes from a single morning in 1582. Mitsuhide set out from Kameyama Castle for Honnō-ji (本能寺, ほんのうじ) in Kyoto, where Nobunaga was staying with a small retinue. The attack that followed — the Honnō-ji Incident (本能寺の変, ほんのうじのへん) — ended Nobunaga's life and threw the unification of Japan into a new phase. Mitsuhide's march began here, which makes the castle the starting point of one of the most consequential days in Japanese history.

The castle later served as the headquarters of the Tanba-Kameyama Domain (丹波亀山藩, たんばかめやまはん), the feudal territory administered from it. Hashiba Hidekatsu (羽柴秀勝, はしば ひでかつ), a son of Nobunaga's successor Toyotomi Hideyoshi, died at the castle. After the Meiji period, the remaining structures of the castle were removed or destroyed, leaving the site without its original buildings.

What Stands There Today

Nothing of the original castle buildings survives; the structures that remained were taken down or destroyed after the Meiji period. The site is remembered through monuments rather than architecture. In 2019 a statue of Akechi Mitsuhide was erected at the castle.

Immediately adjacent to the castle site is Ten'on-kyō (天恩郷, てんおんきょう), the administrative headquarters of the Oomoto religion (大本, おおもと). The presence of the religious headquarters beside the castle grounds shapes the character of the area today and is part of what a visitor encounters on arrival.

The Name in Japanese

The full written form of the name as recorded is 亀山城 (丹波国) — Kameyama Castle, in Tanba Province. The bracketed part identifies the province, distinguishing this castle from other places in Japan also called Kameyama. The reading is かめやまじょう, and the romaji is Kameyama-jō.

Broken down character by character:

• 亀 — read かめ (kame) here. It means "turtle" or "tortoise." The same character appears in the name of Kameyama, the city in Mie Prefecture, and in many place names across Japan. The long-lived turtle is a conventional image of endurance, which suits a fortress site.
• 山 — read やま (yama) here. It means "mountain." Together, 亀山 (Kameyama) is a compound place name meaning "turtle mountain." Japanese castle towns very often take their names from a nearby hill, and the element 山 is one of the commonest in Japanese place names.
• 城 — read じょう (jō) here. It means "castle." On its own the character is read しろ (shiro), and in compounds it regularly becomes じょう, as in 姫路城 (Himeji-jō) or 大阪城 (Ōsaka-jō). The change from shiro to jō is a standard sound shift in compound words, so a learner who knows しろ will recognise じょう once the pattern is pointed out.

The bracketed 丹波国 breaks down as 丹 (tan), 波 (ba) and 国 (kuni, "province" or "country"). 丹波 was the old provincial name for the region around modern Kameoka and part of Kyoto Prefecture; the province system was replaced in the Meiji period, but the name survives in the domain name Tanba-Kameyama and in local usage.

Visiting and Context

Kameoka lies a short distance west of Kyoto, and Kameyama Castle is a stop for travellers interested in the Azuchi–Momoyama period and in the Honnō-ji Incident in particular. The site pairs naturally with other Mitsuhide-related places in the Kyoto area, and with the Oomoto headquarters next door, which gives the location a second, quite different layer of interest.

The castle's historical weight rests on 1578 and 1582: the year Mitsuhide built his base for the Tanba campaign, and the year he marched from it to Honnō-ji. A visit is a visit to a site rather than to a standing castle, since the buildings are gone, but the position on the northwestern road into Kyoto makes clear why the place mattered.