Kawanakajima is a great plain in the Northern Japanese Alps at the northern end of the old province of Shinano where the two great Sengoku Era warlords Takeda Shingen and Uesugi Kenshin fought five battles in twelve years (1553-1564) without a conclusive victory for either side.
"Kawanakajima" means "island between the rivers," because the triangular plain is located between the Sai River to the north and the Chikuma River to the south with a range of mountains to the west. More importantly for Japanese History, the plain was also located right at the border of Uesugi Kenshin's domain of Echigo, and Takeda Shingen's domain of Kai. Kenshin's lands ended at the Zenkoji monastery just to the north while Shingen's domains ended at Kaizu Castle to the south, making Kawanakajima a no-man's land of sorts.
The First Battle of Kawanakajima - 1553
In June, 1553, Shingen launched an exploratory raid into the southern end of the Kawanakajima plain. The vanguard of his army encountered the bulk of the Uesugi army near a Hachiman Shrine but wisely withdrew. The two armies then jockied for position for two months. They briefly clashed at Fuse, but neither warlord felt confident of victory so both withdrew. As Shingen retreated back toward the south, he was dealt a minor defeat by Uesugi forces near the Hachiman shrine.
The Second Battle of Kawanakajima - 1555
Two years later, Shingen tried again, advancing a force of 3,000 men across the Kawanakajima all the way to the banks of the Sai, where he occupied a strategic hill called Otsuka. Kenshin's army was based on another hill, Shiroyama, across the river and just east of the Zenkoji. Eventually, Shingen marched his army down to the banks of the Sai, intending to cross into Kenshin's domain, but Kenshin checked him by moving his own army into position on the opposite bank. From August to November of 1555 the two great warlords glared at each other across the river, their armies entrenched in defensive positions, each waiting for the other to make the first move. There were a few small skirmishes, but neither warlord was willing to commit large bodies of men, and finally the two lords retreated after a four-month stalemate.
The Third Battle of Kawanakajima - 1557
Growing ever bolder as his power increased, Shingen launched his most daring campaign yet in 1557, penetrating deep into Uesugi territory, crossing the Sai and capturing the mountain fortress of Katsurayama, which overlooked Zenkoji, where Kenshin's army was based, from the north-west. But Kenshin seemed unfazed, and declined to fight. Shingen then attempted to take Iiyama Castle to the north-east of the Zenkoji and thus threaten Kenshin from two sides, but when Kenshin finally counterattacked in force, Shingen again chickened out and withdrew.
The Fourth Battle of Kawanakajima - 1561
When a text refers to "The" Battle of Kawanakajima, it is more than likely referring to the fourth encounter, which took place in 1561. While comparatively little is known of the other four battles, the fourth battle was described in the Koyo Gunkan, an epic history of the Takeda clan attributed to one of Shingen's generals, Kosaka Masanobu.
The Fourth Battle of Kawanakajima was the largest and bloodiest of the lot. This time Kenshin was the aggressor, determined to fight a final and decisive battle and destroy Shingen once and for all. In mid-September 1561 he left his headquarters at Kasugayama Castle with a massive force of 18,000 soldiers and headed south across the Kawanakajima plain.
Kenshin's objective was Shingen's Kaizu Castle, just south of the Chikuma in the present-day town of Matsushiro. Crossing the Sai and the Chikuma unopposed, Kenshin took up a position on Saijoyama, a mountain overlooking Kaizu from the west. It was a very threatening move that he knew Shingen could not ignore. Although he easily could have taken Kaizu Castle, which had a garrison of only 150 samurai, Kenshin's real purpose was to lure Shingen into a decisive battle on the open field. Thus Kenshin fortified his position on Saijoyama and patiently waited for Shingen's response.
Shingen, 90 miles away at his great fortress of Tsutsujigasaki, quickly learned of Kenshin's move from signal fires and messagers, and immediately marched for Kaizu with 16,000 men. He was joined by 4,000 reinforcements from Shinano, swelling his army to 20,000 men, and reached Kaizu 24 days after Kenshin's arrival.
One of Takeda's trusted generals, Yamamoto Kansuke, conceived a plan called "Woodpecker." The plan called for Shingen to divide his army into two forces in an attempt to trap the Uesugi army between them. Kosaka Masanobu, the commander of the Kaizu garrison, was to lead a force of 12,000 up the backside of Saijoyama under cover of darkness and attack the Uesugi from the rear. Meanwhile, Shingen himself was to sneak around to the front of the Saijoyama where he would deploy his men in the mighty "crane's wing," a formation designed to surround and entrap an advancing army and destroy it with flanking arrow and gun fire. If all went well, Masanobu would drive Kenshin's army down the hill, right into the waiting swords of Shingen's host, where he would be obliterated.
At first all went according to plan. Both Masanobu and Shingen managed to get their men into formation in total darkness - a tribute to how well the men must have been trained. Shingen sat in his headquarters tent and waited for dawn, when Kenshin's army would come fleeing down the mountain and right into his hands.
But the clever Kenshin had not been idle. His spies had noticed Shingen's force on the move during the night, and Kenshin must have guessed at least part of the plan. Under cover of the morning fog, Kenshin and a force of 10,000 men crept down the mountain and took up position directly in front of Shingen's position. As the fog broke, Kenshin's men attacked. Instead of seeing a the battered, disorganized, and fleeing army he was expecting, Shingen was hit with a fierce head-on assault. Kenshin deployed the devastating "winding wheel" formation, in which units attacked in rounds and as one unit tired it was quickly replaced by another. Kenshin's men tore through the Takeda like a chainsaw.
Outnumbered and outmaneuvered, things looked very grim for the Takeda. The seventy-year old, one-eyed Yamamoto Kansuke, realizing his plan had been a total failure, decided to make amends the samurai way. Taking up a long spear, he charged alone into the midst of the Uesugi, where he fought fiercely until, badly wounded but his honor restored, he retired to a nearby knoll and committed seppuku.
By now, The Uesugi soldiers had penetrated into Takeda's headquarters. Legend has it that Uesugi Kenshin himself came upon Takeda Shingen and the two lords fought a hand-to-hand combat. Takeda was completely surprised and, unable to draw his sword in time, had to use his war-fan to fend off Uesugi's blows. Takeda received three cuts on his body armour and seven on his war-fan before one of his hatamoto finally managed to drive Kenshin away. The site of this encounter is now known as the "three sword seven sword place" and is commemorated with a statue depicting this famous encounter.
Meanwhile, Masanobu's force finally realized what was happening and mounted a desperate attack to save Shingen. But first they had to get through another force of 3,000 Kenshin had prudently left to defend his rear, commanded by one of his best generals, Amakatsu Kagemochi. Although Amakatsu fought stubbornly, his force was overwhelmed by the numerical superiority of Masanobu's force of 12,000. In the nick of time, Masanobu's force fell on the rear of Kenshin's army and drove them from the field. Shingen was saved.
On the morning of the following day Kenshin sent three of his generals, Naoe, Amakatsu, and Usa, to burn what remained of their encampment on Saijoyama. Takeda Shingen, his army weakened, made no attempt to stop them, nor to interfere with Kenshin's subsequent withdrawal beyond the Sai to the Zenkoji, and, a few days later, back to Echigo province itself.
The Takeda were the last army on the field, and thus had nominally won the day, but it was a Pyrrhic victory at best. Although Kenshin's army had suffered devastating 72% casualties, the Takeda, supposedly victors, lost 62% (10% was typical for samurai battles), including several of their most able generals. One of the biggest and bloodiest battles in Japanese history was over, yet another draw.
The Fifth Battle of Kawanakajima - 1564
Shingen decided to try one more time in 1564. That September, Shingen advanced into the Kawanakajima plain and set up camp on a hill called Shiozaki. Kenshin responded and they faced each other once again across the Sai. Both armies sat there for sixty days, and after some light skirmishing, withdrew yet again. It was the fifth and final Battle of Kawanakajima, as Shingen and Kenshin increasingly became pre-occupied with other, less formidable enemies.