This is the site of a flatland castle from the Sengoku period, spanning Aisai City and Inazawa City in Aichi Prefecture. It was built as a base for the "Oda Danjo-chu family," who served as magistrates for the Oda Yamato-no-kami family, the deputy governor of Owari Province.
• Birthplace of Oda Nobunaga
While Nagoya Castle was once considered his birthplace, recent research strongly suggests that Nobunaga was born at this Katsuhata Castle before his father, Nobuhide, moved his base.
• Castle Structure
At the time, it was a strong flatland castle surrounded by a double moat and was also a strategic point for water transport utilizing the surrounding rivers.
• Current State
Although the site is now a residential area and no original buildings remain, a stone monument and information board have been erected at the castle site.
Oda Nobunaga was born here in 1534 (Tenbun 3).
Shohata Castle was built by Oda Nobunaga's grandfather, Nobusada, around the Eisho era (1504-1521) and served as a base for water transportation. It's said that the area was originally called "Shiobata" (salt fields) but that this was a misspelling, or that Nobusada or his eldest son, Nobuhide, renamed it "Shohata," meaning "victory flag," because it was considered unlucky.
The castle is surrounded by a double moat and was the base of the Oda clan, one of the three Kiyosu magistrates. It was a flat castle symbolizing the economic power that controlled the commercial areas of Tsushima and Atsuta, and a certain nobleman invited by Oda Nobuhide in 1533 (Tenbun 2) was said to have been astonished by the castle's size and construction.
Between April 1526 and June 1527, Nobuhide was given the family headship and became its head, growing in power and becoming a Sengoku daimyo. In 1538, he captured Nagoya Castle and moved his base there, appointing one of his vassals to Katsubata Castle as its castellan.
When Kiyosu Castle later became the base of the Katsubata Oda clan, Katsubata Castle gradually fell into decline. This castle, which provided the economic foundation for the Oda clan's development as a Sengoku daimyo, was eventually abandoned.
Until now, it was common knowledge and the established theory that the birthplace of Oda Nobunaga, the turbulent figure of the Sengoku period, was Nagoya Castle. However, based on historical documents discovered afterward, Shobata Castle is now considered the more likely birthplace. If this is true, then Nobunaga was born not in the center of Owari Province, but in a more western area geographically closer to Ise Province.
In short, the Oda Danjo-chu family, to which Nobunaga belonged, was still relatively insignificant at the time. They were one of the three magistrates serving the Kiyosu Oda clan, the deputy governors of the Owari Province, the Shiba clan.
Later, using Shobata Castle as initial capital, his father Nobuhide rapidly rose to power, becoming as powerful as his lord's family. It is a memorable castle that can be considered the origin of the Danjo-chu family. I have to go see it! (laughs)
Actually, I've been calling it "Katsuhata" Castle all this time (laughs). The correct pronunciation is "Shobata" Castle. I thought the name was a bit of a stretch, but there was a reason.
The original place name was "Shiohata" (salt field). It was probably a barren land unsuitable for cultivation due to the high salt concentration in the soil and irrigation water. Because it was considered unlucky, Nobuhide or his father, Nobusada, changed the name to "Kachihata" (victory flag). So, "Katsuhata" wasn't entirely wrong, was it? (laughs)
The castle measured 29 ken east-west and 43 ken north-south (approximately 53 x 78m), surrounded by a 5.5m wide earthen rampart and defended by a double moat. It was such a magnificent castle that Yamashina Tokitsugu, a court noble invited by Nobuhide, recorded his astonishment at its size and construction in his diary.
At this time, in addition to the court nobles of Kyoto, gentlemen and ladies from the surrounding areas were also welcomed to the castle, where they enjoyed elegant pastimes such as linked verse poetry and kemari (a type of ball game). However, the diary of Yamashina Tokitsugu, which recorded the details of the banquet, became the "decisive factor" in identifying Nobunaga's birthplace.
Nobunaga's birth year is 1534 (Tenbun 3), but the diary entry indicates that Imagawa Ujitoyo, the lord of Nagoya Castle, also participated in this banquet held in 1533 (Tenbun 2) and met with Tokitsugu.
It seems unlikely that Nobuhide could have severed ties with them, captured the castle the following year, moved his base to Nagoya, and given birth to Nobunaga there. Currently, it is estimated that Nobuhide acquired Nagoya Castle in 1538 (Tenbun 7).
Unfortunately, the once-prosperous Katsuhata Castle has completely disappeared due to river improvements and land consolidation, literally leaving no trace. A stone monument inscribed with its history remains as a faint reminder of that time. The intricate network of waterways and the overwhelmingly flat terrain were striking.
If you're still not satisfied (lol), you can visit the nearby Tsushima Shrine and imagine the prosperity of the area when young Nobunaga likely ran around. The famous Oda family crest, the "Mokko crest," is the same as the "divine crest" of Tsushima Shrine, highlighting their deep connection. Furthermore, the Danjo-chu family's rise to power stemmed from their control over Tsushima, a town said to be the wealthiest in Owari Province, which prospered through water trade.
It's highly probable that Nobunaga himself played here, making it a place worth visiting in conjunction with the castle ruins.
