Saturday, September 06, 2008
Sengoku Daimyo Takeda Shingen and Uesugi Kenshin are two well known figures from Japan's Sengoku period who fought five battles on the Kawanakajima plain in Shinano province (Modern day Nagano prefecture) between 1553 and 1564. (The fouth battle was depicted in the 1990 Kadokawa Haruki movie Heaven and Earth) Why did Kawanakajima become the main battleground for these two warriors? What made Kawanakajima such a contested area? I thought I'd tackle this question for my blog post this week. After a combination of poking around and deductive reasoning, I can come up with a few reasons. Although, there is no way to really know which reasons might be correct, a little theoretical guesswork never hurt anyone.
1. Shingen was looking to expand his territory. Just like every other Sengoku Daimyo, Shingen wanted to expand his lands. More lands meant more rewards for his retainers, which meant more loyalty, as well as more resources. Kai province, Shingen's home province (Modern day Yamanashi prefecture), did not have ocean access, and as such was at a disadvantage (the need for salt would be an example of a critical disadvantage, and the lack of a ready supply of fish could also be seen as a disadvantage. The lack of access to ocean trade, yet another). In 1554, Shingen entered a three-way alliance with the Hojo and Imagawa, which effectively cut him off from direct ocean access to the south. His only option for direct ocean access would be to go North - Through Shinano and Echigo, through Kenshin's territory.
2. Uesugi Kenshin was the only Daimyo powerful enough to stand up to Shingen. Shingen handily defeated Murakami Yoshikiyo and Ogasawara Nagatoki, leaving Kenshin the only roadblack between Shingen and domination of Shinano province. From a military standpoint, the plain of Kawanakajima was a key route between both Shingen and Kenshin's territory. The Kawanakajima plain was a mere 60 kilometers from Kenshin's home castle of Kasuga, and an occupation by Shingen here could have proved extremely dangerous. From Shingen's standpoint, Kawanakajiima would be a key access point to block southern movement by Kenshin.
3. Kawanakajima was an important key intersection of politics and trade. The Kawanakajima plain falls between the Sai and Chikuma rivers, and are fertile and productive lands. Also, the roads of Kai, Kozuke, and Echigo all intersect here. It was an important highway for the politics and economics of Mino and Totomi provinces. It would also be an important launch pad for Shingen's invasion of Echigo, or a strike south by Kenshin.
The main cause here is Shingen's military aggression. Shingen was, by default, the aggressor. As mentioned above, he wanted ocean access, and to expand his lands. He was boxed in, and after the Alliances of 1554, had nowhere to go but North. Peace with Kenshin would have meant the end of Shingen's expansion, and based on the experience of other Daimyo during the sengoku period, could have meant the end of Shingen. It is likely he had to keep his generals busy with war, or have them turn on him in eventual dissatisfaction. So it is even possible that ocean access might have been a lesser motivation than simply keeping his army busy. Despite this, Shingen still suffered the rebellion of three vassals, Katanuma Nobumoto, Obu Toramasa, and his son Yoshinobu.
Regardless of the reasons, five battles were fought at Kawanakajima, and neither Shingen nor Kenshin were allowed to overtake the other or realize their full potentials as Daimyo. They canceled each other out, and at least in Shingen's case, his expansion was stalled a decade or more, leaving the field open to Oda Nobunaga, who would eventually outdo them both.
A few references for this post:
Kanaya, Shunichiro. Sengoku Jidai Ga Omoshiroi Hodo Wakaru Hon, 2003
Narumoto, Tatsuya. Sengoku Bushou Omoshiro Jiten, Japan, 1998
Takeda Shingen - S-A Wiki