Sakamoto-jo Castle (坂本城)

Nagahide NIWA, Nagamasa ASANO
Mitsuhide AKECHI, Nagahide NIWA, Ietsugu SUGIHARA, Nagamasa ASANO
stone walls, well, ankyo (culvert), foundation stones, structures and other things

Sakamoto-jo Castle is the castle that existed in Sakamoto, Shiga County, Omi Province (in Sakamoto-joshi Park [Sakamoto-jo ruins of a castle park] 3-chome, Shimosakamoto, Otsu City, Shiga Prefecture). It is a hira-jiro (a castle built on level ground) that faced Lake Biwa and was built by Mitsuhide AKECHI.


Sakamoto-jo Castle was located on the west side of Lake Nanko of Lake Biwa in the northern part of Otsu City. As the place faces the mountain range in the west that Mt. Hiei belongs to and Lake Biwa in the east, it was a natural fort. Mt. Hiei stretches to Omi Province and Yamashiro Province, and two roads of Shiratori-do and Yamanaka-do connected the two provinces. The roads were frequently used during the medieval and early modern period, so Sakamoto thrived as a port town for cargo shipment through Mt. Hiei and a key point for transportation.

Presently, most parts of the place where the castle used to be have been developed as residential areas, and National Route 161 runs through the center of the estimated place of Sakamoto-jo Castle.

In 1571, after the fire attack against Enryaku-ji Temple on Mt. Hiei, the land of Shiga County, Omi Province was given to Mitsuhide AKECHI, and Sakamoto-jo Castle was built by the order of Nobunaga ODA as a defense against the forces of Kyo (the capital) and Enryaku-ji Temple on Mt. Hiei. Luis FROIS, a missionary, described in his book "History of Japan" that the great castle was the second most magnificent and gorgeous next to Azuchi-jo Castle.


In September, 1571 Nobunaga ODA ordered Mitsuhide AKECHI, who had been the lord of Usayama-jo Castle, to govern Shiga County and to build Sakamoto-jo Castle. It is estimated that the purpose of this order was to observe the activities of Enryaku-ji Temple on Mt. Hiei and to acquire the marine control of Lake Biwa. According to "Choronicle of Eiroku Era," there is a description that "AKECHI built a castle in Sakamoto, governed the estate and cut down the trees on the mountain." The estate means the estate of Enryaku-ji Temple, and it is estimated that the construction of Sakamoto-jo Castle was stared in 1571 after the fire attack against Mt. Hiei. Also, according to the description of "Kanemi-kyo Ki" (The Diary of Kanemi YOSHIDA) on February 4, 1573, there is a description that "明智見廻の為、坂本に下向、杉原十帖、包丁刀一、持参了、城中天守作事以下悉く披見也、驚目了." By this description, it is known that Sakamoto-jo Castle had a tenshu (main keep or tower of a castle), and it is considered that the construction of a tenshu was well under way by January 1573 after the construction of the Castle started. From his sentence, though it is short, the surprise at the magnificence of the castle by Kanemi YOSHIDA, the author of "Kanemi-kyo Ki," can be imagined. Also, Sakamoto-jo Castle was mentioned by Luis FROIS, one of the missionaries of the Society of Jesus, in his book titled "Frois's History of Japan" as follows. "Akechi built his residence and castle in the place called Sakamoto on the shore of the huge lake which is more than 25 legua in length and about four legua from Kyo and near Mt. Hiei in Omi Province." It seemed that it was the second most magnificent and gorgeous castle for the Japanese next to the one built by Nobunaga ODA on Mt. Azuchi, and that it was more famous than any other castle in Japan. Although this is Luis FROIS's personal impression, Sakamoto-jo Castle was recognized as no less magnificent than the great Azuchi-jo Castle.

Later Mitsuhide AKECHI aimed to suppress Omi Province based on Sakamoto-jo Castle. From 1572 through 1573, he attacked and defeated Kido-jo Castle and Tanaka-jo Castle (Omi Province), and he also attacked the Asai clan on the northern shore of Lake Biwa with battle ships and damaged the clan. After that, Akechi attacked Ishiyama-jo Castle and Imakata-jo Castle and gained almost all of the shore of the southern part of Lake Biwa. Later Sakamoto-jo Castle was used as an important military facility as a defense against the anti-Nobunaga ODA forces. After obtaining almost all of Tanba Province in the Battle of Kuroi-jo Castle, he became the lord of Kameyama-jo Castle in 1580. But it seems that he kept being the lord of Sakamoto-jo Castle as well.

On July 1, 1582, he did not leave for the attack on the Chugoku region, instead he attacked the army of Nobunaga ODA in Honno-ji Temple, and he drove his lord Nobunaga into the fire. Then he attacked Nobutada ODA in Nijo-jo Castle and forced him to kill himself. However, defeated in the Battle of Yamazaki on July 12 in the same year, he temporarily retreated to Shoryuji-jo Castle. Then it is said that while returning to Sakamoto-jo Castle, he was attacked by peasants and killed around Ogurisu in Yamashiro Province. On the other hand, Hidemitsu AKECHI who had become the lord of Azuchi-jo Castle moved to Sakamoto-jo Castle to know his father's defeat in the Battle of Yamazaki. Surrounded by the army of Hideyoshi TOYOTOMI, Hidemitsu AKECHI set a fire on the tenshu by himself and killed himself and Mitsuhide's wife and children.

Later, Hideyoshi HASHIBA ordered Nagahide NIWA to rebuild the castle and Hideyoshi became the lord of it. After that, the castle was used as the military base for the Battle of Shizugatake. Later Ietsugu SUGIHARA and Nagamasa ASANO became the lord of the castle successively. It is considered that the castle town was formed at around this period. However, in 1586 the castle was disposed with Nagamasa ASAI's building Otsu-jo Castle under the order of Hideyoshi. The components of the castle were used for building Otsu-jo Castle. It was 15 years after the castle was built.

"Nobunaga Sengoku Omi" introduces two reasons for the disposing. One reason is because Hideyoshi TOYOTOMI allowed the restoration of Sanmon (Enryaku-ji Temple) in 1584. This is because of the fact that there was less of a need to observe Sanmon. The other reason is that as Osaka-jo Castle was built from 1583 to 1588, the place of Otsu was recognized as more important to connect Hokkoku, the Tokai-do Road, and Yodo-gawa River.


Although Sakamoto-jo Castle had played an important role in history, its location and structure were not known for a long time. However, the structure of the castle started to become clear to some extent by the excavation and research conducted in 1979.

Mizu-shiro (castles on lakes or marshes for defensive reasons)
On February 27, 1578, Sogyu TSUDA who was the tea master of Mitsuhide AKECHI was invited to Sakamoto-jo Castle to hold a tea ceremony. According to "Tennojiya-kaiki," the record of the tea ceremony at the time, there is a description to the effect that "went to Azuchi, getting on a gozabune (a roofed pleasure boat) inside the castle." It seems that the water of Lake Biwa was brought into the castle and they directly got on the boat inside the castle and headed for Azuchi-jo Castle. Therefore, it is considered that the castle was a 'mizu-shiro' whose building is on the shore of a lake. Also, on February 22, 1582, when Kanemi YOSHIDA visited Sakamoto-jo Castle, he had some tea in 'sho-tenshu' (small turret). It cannot be immediately claimed that there was a sho-tenshu at the castle just by this claim.
But "Nobunaga Sengoku Omi" introduces the castle by describing 'it must have been a splendid castle with dai-tenshu and sho-tenshu standing side by side.'

Excavation and research

Sakamoto-jo Castle had never been excavated and researched until 1979, so little attention was paid to the ancient structural remnants of the castle. However, as a large scale housing development was planned right in the center of Sakamoto-jo castle, a survey was conducted with the developing plan. The survey set off an intermittent excavation and research that's still ongoing, and the nawabari (castle plan; general term for the layout of a castle and its component structures) of the castle and other things have come to be known little by little.

In the survey conducted in 1979, a layer of 10 to 30cm deep scorched soil was found. It is considered that the soil was scorched when Hidemitsu AKECHI killed himself with Mitsuhide's wife and his children by setting the tenshu on fire. Over the layer of scorched soil, there is a layer of leveled ground, which is considered to be the remnants of the period of Nagahide NIWA. The following have been found.

The layer under the scorched soil (the part belonging to the period of Mitsuhide AKECHI)
foundation stones of four structures
a fence
a well made of stones
a gutter made of stones
The layer over the scorched soil (the layer belonging to the period of Nagahide NIWA)
foundation stones of two structures
a structure with hottate bashira (earthfast post)
a gutter made of stones
tamemasu (a stone box for sewage to dwell) made of stones
stone wall
There is a strong possibility that, inferring from the scale and placement of the foundation stones, the remnant excavated in the hon maru (the keep of a castle) area is a residential remnant. It is highly possible that hon maru, the main part of the castle, was actually lived in. In addition, in this part of the castle many relics were excavated such as roof tiles, pots, earthenware pots, bowls, basins, mortar, tenmoku tea bowls including seiji (celadon porcelain), seihakuji (bluish white porcelain) and hakuji (white porcelain), which are considered to have been imported from China. Judging from these relics it can be imagined that people in the castle at that time lived a lavish life. Also, metal ware such as coins, mirrors, accouterments of swords, and tacks were unearthed. These unearthed articles were estimated to be the things belonging to the period of late Muromachi through Azuchi-Momoyama.

Sakamoto-jo Castle has many similar features with Otsu-jo Castle and Zeze-jo Castle in terms of nawabari in that it faced Lake Biwa and that the hon maru was positioned in its tip section. It is considered that this is because Sakamoto-jo Castle preceded the two other castles.

Access to the castle site

Access by train
About a ten minute walk from Hieizan-Sakamoto Station of West Japan Railway Company Kosei Line
About a 15 minute walk from Sakamoto Station (Shiga Prefecture) of Keihan Electric Railway Keihan Ishiyama-sakamoto Main Line
Access by car
From Shigasato ramp of Nishi-otsu Bypass to National Route 161
There is a free parking area in Sakamoto-joshi Park (Sakamoto-jo castle ruins park).

[Original Japanese]