Battle of Mikatagahara
The Battle of Mikatagahara was one of the most famous battles of Takeda Shingen's campaigns, and one of the best demonstrations of his cavalry-based tactics. It was also one of Tokugawa Ieyasu's worst defeats, and complete disaster was only narrowly averted.
According to the Japanese calendar, the battle was fought on the 22nd day of the 12th month of the 3rd year of Genki.
Background
In October 1572, after having concluded alliances with his rivals to the east, and after waiting for the snow to close off the northern mountain passes against his northern rival, Uesugi Kenshin, Takeda Shingen led an army of 30,000 men south from his capital of Kōfu into Tōtōmi Province, while Yamagata Masakage led a second force of 5,000 men into eastern Mikawa Province. They quickly captured Yoshida Castle and Futamata Castle.Shingen was opposed by Tokugawa Ieyasu, based at Hamamatsu Castle with 8,000 men, plus an additional 3,000 reinforcements received from his ally, Oda Nobunaga. However, Takeda's intent was not to attack Ieyasu nor to seize Hamamatsu; rather, he wished to avoid conflict if possible to save his forces to destroy Nobunaga and to march on Kyoto.
Takeda's first attack
Against the advice provided by Sakuma Nobumori and Takigawa Kazumasu, who had been sent by Nobunaga, and by his own generals, Matsudaira Ietada, Honda Tadakatsu, Sakai Tadatsugu, and Ishikawa Kazumasa, Ieyasu refused to allow the Takeda to pass through his territory unhindered, and drew up his forces on a high plain called Mikatagahara, just north of Hamamatsu.According to the Kōyō Gunkan, the contemporary Takeda military history, Shingen outnumbered Ieyasu three-to-one, and organized his men in the gyorin formation, enticing his opponent to attack. Opposing him, Ieyasu had gathered his available forces and arrayed them in a line. Oyamada Nobushige was in Shingen's vanguard, followed by Naitō Masatoyo and Yamagata Masakage. The third line was commanded by Katsuyori and Obata Masamori, while Baba Nobuharu was in the fourth.
At around four in the afternoon as snow began to fall, Tokugawa arquebusiers accompanied by a number of peasant stone-throwers opened fire upon the Takeda formation. Firearms, still somewhat new to Japanese warfare, were a known deterrent to cavalry assaults. Ieyasu seemed to have expected his superior weaponry to overcome Shingen's overwhelming forces and formation, however, this assumption was quickly dispelled as Naitō Masatoyo's vanguard units attacked and rapidly overran Honda Tadakatsu's segment of the Tokugawa line. Takeda horsemen surged through the opening and quickly assaulted the accompanying Oda reinforcements before wheeling into the Tokugawa rear. Oda reinforcements were immediately overrun and sent into full retreat, with Hirate Hirohide killed and Takigawa and Sakuma fleeing the battle. The Tokugawa left flank, in spite of grievous casualties, refused to yield ground and managed to shrug off the weight of the Takeda right, preventing an overrunning of the Tokugawa center. This would prove, however, to be a rare victory in what was quickly spiraling into an unmitigated disaster for the Tokugawa allied forces.
Takeda's second attack
Shingen then withdrew his vanguard, offering them an opportunity to rest. He then brought forward a new set of horsemen from the army's main body, ordering Takeda Katsuyori, Obata Masamori, and Saegusa Moritomo to lead a two-pronged cavalry charge into the weakening Tokugawa line. They were closely followed by the footsoldier-heavy main body of the Takeda army, whose combined weight drove the already battered Tokugawa army into a disorderly retreat. In an effort to reorganize his rapidly dissolving army, Ieyasu ordered his commander Ōkubo Tadayo to plant his golden fan standard upon a hill and rally his troops towards the castle town of Saigadake. He then sought to personally re-engage the Takeda army to free his trapped general Mizuno Tadashige, but was persuaded by Natsume Yoshinobu to retreat; as head of the Tokugawa clan, Ieyasu's life was too important. Yoshinobu then led a suicide charge against the Takeda army to buy time for Ieyasu's retreat, and was killed. Other notable Tokugawa retainers killed in the fighting were Naruse Masayoshi, Toyama Kosaku, and Endo Ukon, who all perished as their units were encircled and overrun by the Takeda forces.Tokugawa's retreat
When Ieyasu returned to Hamamatsu Castle, he was accompanied by only five men. The town was on the verge of panic as rumor had already reached Hamamatsu that the battle had gone badly. Nevertheless, Ieyasu commanded that the castle gates remain open, and that braziers be lit to guide his retreating army back to safety. Sakai Tadatsugu beat a large war drum, seeking to add encouragement to the returning men of a noble, courageous retreat. When the Takeda vanguard, led by Baba Nobuharu and Yamagata Masakage heard the drums, and saw the braziers and open gates, they assumed that Tokugawa was planning a trap, and so they stopped and made camp for the night.Tokugawa's counter attack
In the night, a small band of about one hundred Tokugawa foot soldiers and 16 matchlock gunners led by Ōkubo Tadayo and Amano Yasukage attacked the Takeda camp, throwing the vanguard of the Takeda army into confusion. Uncertain of the remaining strength of the Tokugawa forces, and worried that reinforcements from Oda Nobunaga or Uesugi Kenshin were on their way, Takeda Shingen decided to withdraw his forces back to his own territories and to try again the following year.According to the Kansei Chōshū Shokafu, a genealogy of major samurai by the Tokugawa shogunate, Hattori Hanzō rendered meritorious service during the Battle of Mikatagahara, He captured a Takeda spy named Chikuan, and counterattacked Takeda's troops with only thirty men at the Tenryū River.
However, for Shingen, there would be no following attack on Hamamatsu, as he would be fatally wounded in January 1573 at the Siege of Noda Castle.