Local people are maintaining the ruins for visitors.
Later History
The ruins of Ichinomiya Castle were designated as a Prefectural Historic Site of Tokushima Prefecture in 1954. Since then, the local Society for the Preservation of the ruins has been developing them such as maintaining the trail and cutting the grass regularly. That’s why we can always visit the ruins in a comfortable environment. Tokushima City has also been researching the ruins since 2017. The foundations of the castle buildings were found and how the castle was developed is being revealed.
My Impression
After visiting the three most popular castle ruins in Tokushima Prefecture, I noticed that they all once became the capital of Awa Province – Shozui Castle (up to1582), Ichinomiya Castle (from 1585 to 1586) and Tokushima Castle (from 1586). However, they also all have quite different features from each other. This is because the situation of Awa Province changed greatly in a very short time. The needs for castles also changed rapidly at that time. I recommend visiting the three castle ruins and comparing them.
How to get There
If you want to visit there by car: It is about 20 minutes away from Aizumi IC on Tokushima Expressway. You can park at the Ichinomiya Shrine or the Dainichi-ji Temple. By public transportation, take the Tokushima Bus on the Kamiyama Line bound for Yoriinaka from JR Tokushima Station and get off at the Ichinomiya-fudasho-mae bus stop. If you go there from Tokyo or Osaka, I recommend traveling by plane or using an express bus.
Ichinomiya Clan built it in Period of Northern and Southern Courts
Ichinomiya Caste was the largest mountain castle in Awa Province (what is now Tokushima Prefecture) on Shikoku Island. It is said that The Ichinomiya Clan first built the castle in the 14th Century during the Period of the Northern and Southern Courts. Many battles happened across the county, so warriors started to build mountain castles to protect themselves. After the governance of Awa Province got stable, The Ichinomiya Clan seemed to live in a hall at the foot of the mountain and used the castle in an emergency like other clans used to do.
The location of the castle
Motochika Chosogabe captured it in Sengoku Period
In the late 16th Century during the Sengoku Period, many battles happened again in Awa Province. Narisuke Ichinomiya, the lord of the Ichinomiya Clan, managed to survive under the Miyoshi Clan, the governor of the province, and partly thanks to Ichinomiya Castle. After that, he changed his mind to support Motochuka Chosogabe. Motochuka who was from Tosa Province in the south, invaded Awa Province in 1582. However, Narisuke was killed by Motochika probably because Motochika doubted Narisuke’s change of mind. Ichhoinomiya Castle was captured by Motochika.
Ichinomiya Castle was not only a large mountain castle but also Akui-gawa River flowed in front of the gate as a natural hazard. It also had a fountain and warehouses inside, so it could be besieged for a long time. It was also near the center of the province. For a warlord who aimed to govern Awa Province by power, it was necessary to get such a strong and good-located castle as soon as possible. Motochika sent one of his senior vassals, Tadazumi Tani, to Ichinomiya Castle to maintain it.
Castle once became Capital of Awa Province
In 1585, the ruler, Hideyoshi Toyotomi sent over 100,000 soldiers to Shikoku Island to capture it. Ichinomiya Castle with about 10,000 defenders was besieged by about 40,000 attackers. The siege lasted for nearly one month and the castle was open as Motochika surrendered to Hideyoshi. Hideyoshi also sent one of his retainers, Iemasa Hachisuka as the lord of Awa Province. Iemasa chose Ichinomiya Castle as his home base, that meant the castle finally became the capital of the province. He built stone walls in the Main Enclosure on the top of the mountain though the castle had been all made of soil. He also built his Main Hall in the Main Enclosure and a building with a veranda in another enclosure, which might have been used for sightseeing.
However, Iemasa moved his home base from Ichinomiya Castle to new Tokushima Castle facing the sea the next year in 1586. It is said this was due to Hideyoshi’s instruction to build the network of sea transportation. The situation rapidly changed after Hideyoshi’s unification of Japan. The peak of Ichinomiya Castle lasted for just one year. After that, the castle was considered one of the branch castles called the Awa Nine Castles while the governance of Awa Province was not stable. The castle was finally abandoned soon after the Law of One Castle per Province by the Tokugawa Shogunate in 1615.
Tokushima Castle was located in what is the modern day Tokushima City. The prefectural capital of Tokushima Prefecture is Tokushima City. The old name for Tokushima Prefecture was called Awa Province, where the Chosokabe Clan and the ruler, Hideyoshi Toyotomi battled in the late 16th Century during the Sengoku Period. Hideyoshi finally won and he gave the province to his senior vassal, Iemasa Hachisuka in 1585. Iemasa first lived in one of the major mountain castles, called Ichinomiya Castle, but he soon moved to another place in 1586, building a new castle named Tokushima Castle.
The location of the castle
building network of sea transportation
Tokushima Castle was built on Inoyama Mountain which was 62m high on a sandbank called Inotsu. The sandbank was among the delta of Yoshino-gawa River, the largest river in Shikoku Island. The place where the castle was built was not spacious for the lord of the province. It was said that Hideyoshi suggested that the castle should be built at that place. So why did he instruct Iemasa to build the castle at such a place? Historians speculate that Hideyoshi tried to build the network of sea transportation with his home base, Osaka Castle. Tokushima was renamed by Inotsu and had a location which was capable of controling the sea lanes such as Kii Channel. The area was the entrance to Osaka Bay in which Osaka Castle was facing. The network consisted of both navy and merchant fleets. Another possible reason was that The Hachisuka Clan still had to send their retainers to branch castles called the Awa Nine Castles against the resistances of Chosokabe. That meant Hachisuka’s home base didn’t need a large space.
The relief map around the castle, Inoyama Mountain stands out among the delta
The positional relation between Tokushima Castle and Osaka Castle
Center of Castle was once on Mountain
Inoyama was a dogleg mountain which extended from the east to the west. The Main Enclosure was on the highest, the largest and rounded part of the mountain, which was thought to have the first Main Tower and the first Main Hall for the lord. However, the Main Tower was scraped about 30 years after its foundation for some unknown reasons and rebuilt in the Eastern Second Enclosure of the lower eastern part of the mountain. This was a very rare case because most castles had their Main Tower at the highest point of the mountain. There’s only one other castle that had a similar case, which was Mito Castle. However, its reason was more obvious. Its main reason was that it was small and inconvenient. The western part of the mountain also had the Western Second Enclosure and the Western Third Enclosure that protected the Main Enclosure. These enclosures on the mountain got surrounded by stone walls one by one. On the other hand, the plain area on the sandbank in the south of the mountain was not fully developed. Experts speculate that there were probably two main halls instead of one primary hall on the mountain. This secondary hall on the plain area was used as the home of the lord and its warriors. Tokushima Castle was specifically designed for battles that took place during the first generation of its existence.
The aerial photo around Mito castle
Center of Castle moves to plain area
After the Tokugawa Shogunate defeated the Toyotomi Clan in 1615, the governance of the shogunate finally became stable. The Hachisuka Clan was also able to spread their territory by adding the Awaji Province through supporting the shogunate. Due to the long period of peace, The nine branch castles were eventually abandoned. As a result, the retainers gathered in Tokushima Castle which needed to be reconstructed. The large scale of the Main Hall for the lord was rebuilt on the plain area and became the center of the castle. It was also surrounded by stone walls with several turrets, and fences called Byobu-bei along with the Inner Moat and the Terashima-gawa River. The southern side of it had the Kuro-mon Gate as its main gate with the three-story turret called Taiko-yagura next to it, which looked like the main tower. In addition, there was also the Miki Enclosure in the south of the Main Hall with the front gate called Washi-no-mon. Many of the rivers around the castle were also reclaimed and turned into the warriors’ residences and the castle town. The Hachisuka Clan lived in the castle until the end of the Edo Period.