164.洲本城 その1

淡路島にある素晴らしい城

立地と歴史

独立した淡路国に築かれた城

洲本城は、日本の本州と四国、そして2つの細い海峡(明石海峡と鳴門海峡)に挟まれた淡路島にありました。また、淡路島は播磨灘、大阪湾、紀伊海峡にも囲まれています。この島は、日本の中心とされた京都にも近く、近代以前には、特に海上交通をコントロールしたり監視したりするための重要な拠点と見なされていました。その結果、淡路島は、淡路国として独立した国となっていました(現在では兵庫県の一部となっています)。

城の位置

戦国時代の16世紀、三好氏の配下であった安宅(あたぎ)氏が最初に洲本城を築き、水軍を率いました。しかし、安宅氏は1581年に天下人の豊臣秀吉に降伏しました。秀吉は(一旦仙石久秀にこの城を与えますが)最終的には1585年に、部下の脇坂安治(わきざかやすはる)を洲本城に送り込みます。安治は、大洲城に転封となる1609年までの24年間、洲本藩の藩主としてこの城を統治しました。

脇坂安治肖像画、龍野神社蔵 (licensed under Public Domain via Wikimedia Commons)

脇坂安治が大幅に強化

洲本城は、もともと土造りの単純な山城であり、三熊山の上に築かれました。その頂からは、周辺の海域(東側の大阪湾と南側の紀伊水道)を見渡すことができます。安治は、洲本城を大幅に改修し、山の上に石垣や天守を含む多くの櫓を築きました。こういった城の構造は、秀吉やその部下たちによって成された典型的な築城方法でした。この築城方法は、秀吉の天下統一事業の間、日本中に広まりました。城をより強化することで、人々に権威を誇示していたのです。安治はまた、山麓に御殿を築き、城下町を開設しました。彼は最後に、登り石垣と呼ばれる階段状の石垣を、山麓と山頂をつなぐ直通ルートとして建設しました。登り石垣は、安治を含む数名の大名が、朝鮮侵攻の際、連絡あるいは防衛のために開発したものです。洲本城にあるものは、現存する数少ない登り石垣の一つです。安治は、日本に戻った後、登り石垣を洲本城に応用したのです。これにより、洲本城は完成したとされています。

城周辺の起伏地図

本丸の石垣
登り石垣

一時は廃城に

ところが、安治が転封となった後、洲本城は他の大名たち(池田氏、蜂須賀氏)によって使用されませんでした。これは、淡路国がその大名たちの所領の一部になったこと(池田氏は播磨国、蜂須賀氏は阿波国が本拠)、淡路国では他の城を支城として使ったこと(岩屋城や由良城)がその理由です。更には、洲本城は、1615年に徳川幕府により発せられた一国一城令により一時廃城となってしまいます。山上の全ての建物は、当時淡路国と阿波国(現在の徳島県)を治めていた蜂須賀氏によって撤去されました。一説によると、洲本城が廃城となる前に、その天守が脇坂安治により大洲城に移設されたとのことです。大洲城の天守の形式が、安治が洲本城にいた時に一般的であった天守の形式の一つに該当するそうです。

淡路島にあった支城群の位置

大洲城

蜂須賀氏の支城として石垣を維持

1631年、蜂須賀氏は、何らかの理由で洲本城を淡路国の支城として復旧しました(交通の便のためとも言われています。それまで使っていた、大阪湾入口近くにあった由良城は廃城となりました)。蜂須賀氏は、家老の稲田氏を城代として城に派遣しました。しかし、城の中心部は山の麓に設定され、城主の御殿が再建されました(御殿は城主である蜂須賀氏のためであり、稲田氏は別の屋敷に住んでいました)。山の部分は基本的には脇坂氏が築いた石垣のみが維持され、新しい門がいくつか添えられただけでした。これは恐らく、蜂須賀氏にとって、本拠地の徳島城とは違い、洲本城はあくまで支城の一つであり、山上は非常時にのみ必要な場所だったからでしょう。この城の珍しい形態は、19世紀半ばの江戸時代末期まで維持されました。

淡路国(洲)本城下之絵図、江戸時代(出展:国立国会図書館)山上部分は既に石垣のみとなっています
山麓部分の城跡 (licensed by Reggaeman via Wikimedia Commons)

「洲本城その2」に続きます。

77.Takamatsu Castle Part1

One of the three greatest sea castles in Japan

Location and History

Chikamasa Ikoma built Castle based on experience

Takamatsu Castle, one of the greatest sea castles in Japan, was located in Sanuki Province which is now Kagawa Prefecture. The name of the prefectural capital, Takamatsu City, actually originates from this castle. Chikamasa Ikoma, who was a warrior in the 16th Century during the Sengoku Period, first built the castle. Chikamasa took part in many battles such as those at Nagashino Castle, Ishiyama Honganji Temple (former Osaka Castle), and Bicchu-Takamatsu Castle under the ruler Hideyoshi Toyotomi. Chikamasa contributed to the unification of the country by Hideyoshi who gave Chikamasa Sanuki Province in 1587.

The location of the castle

The portrait of Chikamasa Ikoma, owned by Kokenji Temple (licensed under Public Domain via Wikimedia Commons)
The ruins of Nagashino Castle
The present Osaka Castle, which was once Ishiyama Honganji Temple
The ruins of Bicchu-Takamatsu Castle

Chikamasa at first used the existing Hiketa Castle, but he decided to build a new castle as his home base. From his experiences, his concerns about the castle were:
・whether it would be able to get naval support during battles.
・whether it would be able to withstand gun attacks.
・whether it would be able to survive a long siege.
In the end, he devised Takamatsu Castle, which was completed in 1590.

The ruins of Hiketa Castle
The present Takamatsu Castle

Castle surrounded by Sea and Triples Moats

Takamatsu Castle was built facing the Seto Inland Sea to the north, making it possible to ship directly to the sea. The castle was also surrounded by water moats tripled in the other directions, to which the sea supplied water. The main enclosure which had the three-layer main tower was isolated in the inner moat, connecting to the second enclosure with only a wooden bridge called saya-bashi. The third enclosure was next to the second enclosure, which had the gate opening to the sea. The enclosure also had the main hall for the lord of the castle. Such a castle was classified not only as a plain castle, but also a sea castle. It would be impossible for enemies to completely besiege this castle with technology at that time.

The folding screen of Takamatsu Castle and the castle town, owned by Kagawa Prefectural Museum (licensed under Public Domain via Wikimedia Commons)

Matsudaira Clan followed and developed Castle

The Ikoma Clan was allowed to maintain their territory of Sanuki Province for a while by supporting the Tokugawa Shogunate in the battle of Sekigahara in 1600. However, the clan was forcibly moved by the shogunate in 1640 due to their internal strife. After that, the Shogun’s relative, Yorishige Matsudaira was sent to Takamatsu Castle as a replacement for the Ikoma Clan. Though lords were basically not allowed to renovate their castles at that time, he developed and improved Takamatsu Castle by rebuilding the main tower and adding the northern and eastern enclosures. This was because he was also responsible for monitoring non-hereditary feudal lords in Shikoku Island, who might have been against the shogunate.

The old photo of the Main Tower Yorishige rebuilt
Part of the whole illustration of Old Takamatsu Castle, the illustration drawn after Yorishige developed the castle, from the signboard at the site

The Matsudaira Clan governed the castle and the area around as the Takamatsu Domain until the end of the Edo Period. In the peaceful time of the Edo Period, the beautiful view of the castle became a famous attraction for people. A guide book at the time says that the castle looks as if it is a floating castle on the waves from the Seto Inland Sea. The castle has also been said to be one of the three greatest sea castles in Japan.

The miniature model of Takamatsu Castle and the castle town, exhibited by Tamamo Park Museum

To be continued in “Takamatsu Castle Part2”

177.Hiketa Castle Part1

The forgotten castle in the eastern part of Sanuki Province

Location and History

Castle on Mountain supporting Port

Hiketa Castle was located on an 82m high mountain called Shiro-yama in the eastern part of Sanuki Province which is the modern day Kagawa Prefecture. The Hiketa Port, facing the Harima Sea, beside the mountain which could prevent strong wind from blowing into the port. The port became popular amongst ships waiting for favorable wind from the Ancient Times. It was said that the mountain was also used as a fire beacon platform at that time. In the Middle Ages, several lords used the mountain as Hiketa Castle. For example, in 1583, Hisahide Sengoku under the ruler, Hideyoshi Toyotomi fought with Motochika Chosogabe using Hiketa Castle. Overall, the castle was used whenever it was needed. It was built with natural terrain.

The location of the castle

The aerial photo around the castle

The portrait of Hisahide Sengoku, private owned (licensed under Public Domain via Wikimedia Commons)

One of Important Branch Castles in Sanuki Province

During the unification of Japan, Hideyoshi gave Sanuki Province to his retainer, Chikamasa Ikoma in 1587. Initially, Chikamasa lived in Hiketa Castle, but soon after that, he moved to another one, and finally built Takamatsu Castle as his new home base. However, Hiketa Castle was maintained as one of the branch castles of Takamatsu Castle. The stone walls were built surrounding the enclosures on the top of the mountain. Part of them still remain on the mountain. They were specifically built in places where visitors often came and local people could look up from the foot of the mountain. That was the way for Hideyoshi and his retainers to show their authority to the people in their new territories. It was said that the way originated from the castles like Nobunaga Oda’s Azuchi Castle and Nagayosi Miyoshi’s Imori Castle.

The portrait of Chikamasa Ikoma, owned by Kokenji Temple (licensed under Public Domain via Wikimedia Commons)
Takamatsu Castle
The remaining stone walls of Hiketa Castle
The ruins of Azuchi Castle
The ruins of Imori Castle

Some castle buildings were also built on the enclosures, but the details are uncertain because none of them remained. However, it was thought that the buildings looked like those of Takamatsu Castle. That’s because the roof tiles, which were made from the same model, were excavated from both sites. That meant there might have been the three castles which had very similar appearance in Sanuki Province which the Ikoma Clan owned. They were Takamatsu Castle in the center which was their home base, Hiketa Castle in the east, and Marugame Castle, which was the other branch castle in the west. Hiketa Castle was at its peak at the beginning of the 17th Century. The castle town was also built beside Hiketa Port.

Marugame Castle

Abandoned by Law of One Castle per Province

However, Hiketa Castle was abandoned in 1615 due to the Law of One Castle per Province which was created by the Tokugawa Shogunate. Only Takamatsu Castle was allowed to be used from then on. Marugame Castle was once abandoned at the same time as Hiketa Castle. However, Marugame Castle was rebuilt when Sanuki Province was divided by other lords later on. As a result, Hiketa Castle was the only castle that had peace and quiet and stayed idle eventually becoming forgotten for a long time.

The ruins of Hiketa Castle

To be continued in “Hiketa Castle Part2”