Also known as: Kawagoe Night Battle (河越夜戦), Kawagoe Engagement (河越合戦)

The Battle of Kawagoe Castle was fought on May 19, 1546, in Musashi Province at and around Kawagoe Castle, held by the Houjou, against an overwhelming force led by Uesugi Norimasa (Yamanouchi-Uesugi Clan and the then-Kantou Kanrei), Uesugi Tomosada (Ougigayatsu-Uesugi Clan), and Ashikaga Haruuji (the then-Koga Kubou).

When the Uesugi-Ashikaga forces besieged Kawagoe Castle on Oct. 31, 1545, they numbered roughly 70,000-80,000 men to the 3,000 in the castle garrison, led by Houjou Tsunashige. (One account says that all the daimyo of the Kantou except Chiba Toshitane of Shimousa participated.) Ujiyasu led a reinforcement force of 8,000 from Sagami, and the fighting was locked in stalemate for several months. Kushima Tsunahiro (Tsunashige's younger brother), who was in Ujiyasu's reinforcement force, sent a single horseman to slip through the Uesugi-Ashikaga forces into the castle to coordinate a surprise attack.

Ujiyasu sent a false offer of surrender to the Uesugi army. Instead of accepting it, they attacked the Houjou fiercely. Ujiyasu pulled back, luring the enemy into believing they had the battle in hand. On the night of May 19, Ujiyasu split his 8,000 troops into four companies. One of them he left under the leadership of Tame Mototada with the command that it would not move until the end of the battle. Ujiyasu led the other three companies, traveling lightly without armor, into the enemy camp at midnight. The Uesugi-Ashikaga army collapsed in pandemonium. Uesugi Tomosada was killed. When Tame Mototada saw from behind Ujiyasu that he had thrust too far in, he sounded a conch shell to warn Ujiyasu and pull him back. On the other hand, Tsunashige, who had been watching over the battle from inside the castle, led his troops into Ashikaga Haruuji's army, shouting "We've won! We've won!" Occupied with Ujiyasu's army and completely unprepared, the Ashikaga army was routed. The total number of dead on the Uesugi-Ashikaga side reached 13,000 according to some accounts.

As a result of the battle, the Ougigayatsu-Uesugi Clan was destroyed, and Kantou Kanrei Uesugi Norimasa rapidly lost power and influence until he was driven out of Hirai Castle, his main stronghold, and forced to seek refuge with Nagao Kagetora in Echigo. Immediately thereafter, Ashikaga Haruuji was surrounded at the old imperial palace and forced to retired in favor of his son, Ashikaga Yoshiuji, whose wife was Houjou Ujiyasu's daughter.

The Battle of Mimase Pass took place on Oct. 8, 1569 between the armies of the Houjou Clan, led by Houjou Ujiteru and Houjou Ujikuni, and the Takeda Clan, led by Takeda Shingen, after the Kai-Sagami-Suruga alliance fell apart in 1568 upon Takeda's invasion of Suruga.

On Oct. 1, 1569, Takeda Shingen besieged Houjou Ujiyasu's Odawara Castle with 20,000 troops, but like Uesugi Kenshin before him, failed to penetrate the Houjou Clan's main fortress' defenses and retreated four days later on Oct. 5 after setting fire to the land near the castle. Houjou Ujiteru and Houjou Ujikuni set up an ambush with an army of 12,000-20,000 (estimates differ) at the strategic Mimase Pass for the Takeda army as it retreated back towards Kai. Houjou Ujimasa brought up their main army of 20,000 in a pincer movement.

Takeda Shingen led the Takeda army along with his generals Takeda Katsuyori, Takeda Nobukado, Yamagata Masakage, Naitou Masatoyo, Baba Nobuharu, Asari Nobutane, and Obata Norishige.

Houjou Ujiteru and Houjou Ujikuni led the Houjou army along with their generals Houjou Ujitada, Takajou Kurando (?), Hara Tanehide, and Ueda Tomonao.

Ujiteru and Ujikuni apparently sprung the ambush before Ujimasa arrived. Shingen, who had sensed the attack, split his army into three parts: one met the Houjou head-on, while the other two hid in the mountain and attacked from the side. The two armies met in full-blown battle on Oct. 8. The Houjou held the advantage at the start. However, a detached force led by Yamagata Masakage struck in a surprise attack from the higher ground of Shida Pass about a kilometer to the south-west, managing to turn the tide of the battle. The Takeda army also employed arquebuses in the narrow mountain pass to their great advantage, and the Houjou army suffered heavy losses. Though the fighting was close at the beginning of the battle, by the end it was clearly a Takeda victory.

Ujimasa halted his army upon hearing of the Houjou defeat, so the pincer attack (which may yet have won the day for the Houjou) never came to pass. Takeda then pushed forward into Sagami, there to raise his victory shout, before retreating.

Because Uesugi Kenshin had not sent aid during the seige and battle, the Houjou Clan began to view him with distrust, and Houjou Ujiyasu wrote a letter to him expressing his discontent. This battle would become the underlying cause for the Houjou's severing of their alliance with the Uesugi Clan and reformation of their alliance with the Takeda Clan.

Also known as: Realm Divide

The Battle of Sekigahara was fought on October 21, 1600 between the forces of those loyal to Toyotomi Hideyoshi's young son and heir, Toyotomi Hideyori (forces of the West) and Tokugawa Ieyasu (forces of the East). The battle took place in Sekigahara in modern Gifu Prefecture and was the decisive battle which led to Tokugawa taking control of all Japan.

The Battle of Uozu Castle was fought in 1582 between vassals of Uesugi Kagekatsu with 4000 soldiers and that of Oda Nobunaga with more than 10,000 soldiers. The Oda forces, led by Shibata Katsuie, Sassa Narimasa, Maeda Toshiie, and Sakuma Morimasa, fresh from successfully taking Toyama Castle, besieged Uozu Castle around March 11 (March 3, 1582).

The castle commanders immediately beseeched Kagekatsu for help, but Kagekatsu's reinforcements, already depleted by the Otate no Ran, were delayed by the betrayal of Shibata Shigeie and the Oda troops remaining in Kai and Shinano after their subjugation of the Takeda.

The Oda forces weakened the castle with numerous fierce attacks. Kagekatsu personally led an army from Kasugayama Castle on May 4 (May 25, 1582). Two days later, the Oda forces occupied the outer citadel of the castle. On May 19 (June 9, 1582) the Uesugi army arrived on Uozu Castle's east bank and set up camp at Tenjin Hill. However, they could not break through Oda's besieging army, and were forced to withdraw on May 27 (June 7, 1582) when it appeared that Kasugayama Castle itself may come under attack.

Abandoned by Kagekatsu after a 3-month long siege and running out of provisions, the 13 commanders of Uesugi, Sanbonji Kagenaga, Yoshie Munenobu, Yoshie Kagesuke, Yoshie Nobukage, Ishiguchi Hiromune, Nakajou Kageyasu, Takenomata Yoshitsuna, Terashima Nagasuke, Tadenuma Yasushige, Abe Masayoshi (sp?), Wakabayashi Ienaga (sp?), Kameda Choujou (sp?), and Fujimaru Katsutoshi wrote their names on wooden tablets and committed seppuku on June 3 (June 22, 1582). Thus the castle fell to Oda.

The Oda army prepared to march on to Echigo, but news of the death of Oda Nobunaga on June 21, the day before the end of the siege, caused confusion and panic within the army, and it retreated.

<small>Note: Japanese dates given in this entry are based on the lunar calendar; Gregorian Calendar dates in () were calculated using <a href="http://www.uni-tuebingen.de/geschichte-japans/nengo_calc.htm">NengoCalc</a>.</small>