Basically, newer stone walls use more processed stones. However, in the case of those in Nakatsu Castle, it looks like it is the other way around.
Features
Private Company runs Imitation Main Tower
Today, the ruins of Nakatsu Castle have been developed as a tourist attraction called “Nakatsu Castle Park”. This is because the ruins have an outstanding five-level Main Tower on a corner of the stone walls in the Main Enclosure. However, the tower is an imitation, which was built at the place where another original turret had been built. A company, which the former lord of the castle, the Okudaira Clan ran, built it to boost tourism. Because of its origin, it mainly exhibits the history of the Nakatsu Domain under the clan’s rule as the Okudaira Clan Historical Museum. However, when the museum lost money, the clan sold it to another private company. This current castle is considered the only one which a private company runs, so they may approach you. If you want to know much about Yoshitaka Kuroda who was the founder of the castle, you can visit the Kuroda Kanbe Museum which Nakatsu City owns, in front of the tower.
Several kinds of Stone Walls from Kuroda and Hosokawa Periods
The historical items of the castle mainly remain in the Main Enclosure, such as the stone walls and water moats. If you look at the northern side of the stone walls, they are divided into the older part on the right and the newer one on the left. You can clearly see the joint which was the corner of the older part. Basically, newer stone walls use more processed stones. However, in the case of those in Nakatsu Castle, it looks like it is the other way around. The stones in the new left stone walls are natural while those in the older ones are more processed. The reason for it was that the founder, Yoshitaka Kuroda brought the stones from an ancient mountain castle, Tobarusan-jo nearby to build the new castle rapidly.
The aerial photo around the castle
The Main Enclosure is still beside the Nakatsu River but the concrete bulkhead with a promenade is between them now. It may be a good idea to walk on the promenade to see the river and the castle. The stone walls, which use the ancient mountain castle’s stones, lie along the riverside. They were probably built there with castle buildings on them to consider the scenery of the castle from the river. However, you can see modern residence or shrine buildings on them now, which are an interesting contrast. There are the stone walls of the Water Gate at the edge of the enclosure, which makes us understand the castle was directly connected to the river in the past.
There are another type of stone walls which Yoshitaka originally built opposite the riverside. They are long but not so high, built using smaller natural stones than the Hosokawa Clan’s period. They were recently repaired with the water moat in front of them, where you can walk along.
New and Old Entrances of Main Enclosure
In addition, you can see the cut sections of the stone walls at the main entrance of the Main Enclosure with the shrine gate. This is because the entrance was built by breaking part of the stone walls in the Meiji Era and the gate was built in the Showa Era.
There are the ruins of Shiiki-mon Gate, the original main entrance, near the current one, which are still surrounded by stone walls. The gate also had a fan-shaped space for defense, surrounded by other stone walls in the back. However, the stone walls were partially removed.
Yoshitaka Kuroda, who built Nakatsu Castle, is known to many Japanese people as the military strategist of Hideyoshi Toyotomi. However, he was actually a working general and a secretary under Hideyoshi.
Location and History
Yoshitaka works hard for Unification of Japan with Hideyoshi Toyotomi
Nakatsu Castle was located in Buzen Province which is equivalent to the eastern part of Fukuoka Prefecture and the northwestern part of Oita Prefecture. The province was also the northernmost part of Kyushu Island which was connected with the Main Island of Japan through Kanmon Straits. The castle was built on a delta in the estuary of Nakatsu River flowing into Buzen Sea, in the central part of the province, by Yoshitaka Kuroda (he is more often known as Kanbe Kuroda or Josui Kuroda after he retired). He is known to many Japanese people as Gunshi or the military strategist of Hideyoshi Toyotomi who was the ruler of Japan in the end of the 16th Century. However, the degree was given by later people like historians, critics, and novelists, he was actually a working general and a secretary under Hideyoshi.
The range of Buzen Province and the location of the castle
Yoshitaka was originally a senior vassal of a local lord, the Kodera Clan in Harima Province (now the southern part of Hyogo Province). When Hideyoshi invaded the Chugoku Region, which included the province, as a general under Nobunaga Oda, Yoshitaka supported Hideyoshi by providing his own Himeji Castle to Hideyoshi. After that, he did his best to help complete the unification of Japan by Hideyoshi. A famous story about him in the early stage is that he was confined for about one and a half years in Arioka Castle when he visited to persuade Murashige Araki who had decided to be against Nobunaga. While Hideyoshi had become the ruler after Nobunaga was killed by Mitsuhide Akechi, Yoshitaka worked at Hideyoshi’s beck and call. For example, he negotiated with the Mori Clan in the Chugoku Region to divide territories into each other without battles. When the invasion of Kyushu happened in 1587, Yoshitaka set the stage for Hideyoshi’s arrival by fighting against local lords or making them surrender.
Yoshitaka builds Castle in his territory in Bungo Province
After the invasion, Yoshitaka was given part of Buzen Province by Hideyoshi. His territory was small for his contribution so far, because, it has been said it was because Hideyoshi feared Yoshitaka’s potential power. However, some suggest that it could have been because Yoshitaka was a Christian which Hideyoshi had banned from spreading just after the invasion. Yoshitaka at first lived in Umagadake Castle, one of mountain castles which were common then, but launched the construction of Nakatsu Castle in 1588, which would be considered one of the Three Great Sea Castles in Japan, together with Imabari and Takamatsu Castles. Its location was decided by Yoshitaka for the convenience of the government and transportation, but probably also instructed by Hideyoshi. Hideyoshi’s other retainers also built sea castles in their new territories in the Kyushu Region during the same period, such as Kokura, Oita-Funai, and Yatsushiro Castles, which were used for the preparation for the invasion of Korea planned by Hideyoshi as well.
Nakatsu Castle was also one of the earliest modernized castles with turrets and stone walls in the region. The Main Enclosure was in the center but along the estuary and had a gate directly to it, which is a rare case in Japanese castles. The Second Enclosure was in the front of the sea and the Third Enclosure was in the back. All of them were on the delta which looked like a folding fan. The number of the turrets was 22 at its peak, but the Main Tower was not built for some reason.
Did Yoshitaka want to be Ruler?
The highlight of Yoshitaka’s life came when the decisive battle happened in 1600 between the East Quad led by Ieyasu Tokugawa and the West Quad by Mitsunari Ishida after Hideyoshi died. Yoshitaka joined the East Squad with his son Nagamasa, who fought with Ieyasu against Mitsunari in the Battle of Sekigawara in central Japan. Yoshitaka himself stayed at Nakatsu Castle, and after he left, he captured castles in Kyushu, which other lords in the West Squad owned, one by one. The Battle of Sekigahara, where Ieyasu defeated Mitsunari, ended in only one day on the 15th of September. However, Yoshitaka continued to invade the region for about two more months until Ieyasu stopped him. Yoshitaka had already captured all the Kyushu Region with his allies except for the territory of the Shimazu Clan in southern Kyushu. This made people later speculate that Yoshitaka would have liked to be the ruler, but only he knew the answer. The Kuroda Clan was promoted to be the lord of much larger territory of Fukuoka Domain including Fukuoka Castle before Yoshitaka died in 1604.
Castle is followed by Nakatsu Domain which promotes learning Western sciences
Nakatsu Castle was followed by the Hosokawa Clan as their branch castle. The castle survived even after the Law of One Castle per Province, issued by the Tokugawa Shogunate in 1615. It is said this was because Sansai Hosokawa, the father of the lord used it as his retreat. The castle was finally governed by the Okudaira Clan as the Nakatsu Domain until the end of the Edo Period. A remarkable event during the period was that the lords promoted learning about the Western sciences through Dutch language, called Rangaku. Japanese people were usually not allowed to learn them because trading the Western items and communicating with the Western people were strictly limited. Only the trading with Dutch at the Dejima trading house in Nagasaki and visiting Edo by the head of the house every four year were allowed. However, the third lord, Masashika Okudaira started to promote it after seeing his mother’s broken bones were mended by Western medicine. Ryotaku Maeno, who first translated a book of Western medicine with his colleagues such as Genpaku Sugita, was the domain’s doctor. Yukichi Fukuzawa, who was a great philosopher and educator in the Meiji Era, came from lower class samurais of the domain but started in life by learning Rangaku.