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|Next: Battle of Koga|
|Siege of Kawagoe Castle|
|Conflict: Warring States Period|
|Outcome: Hojo victory|
The Hojo clan of Izu Province was a strong clan that was led by Hojo Soun from the 1490s until 1519. When he died, the clan went into a steep decline. In 1545, in a bid to eliminate the Hojo clan, the Uesugi clan allied with the Ashikaga Shogunate and the Nagao clan, and was later assisted by the Takeda clan and the Imagawa clan. The coalition was led by Tomosada Ogigayatsu, although the Uesugi daimyo Norimasa Uesugi was present. The coalition had 80,000 troops, and sent back the peace envoys with contempt. Kawagoe Castle was put under siege by the coalition. The castle's commander Tsunashige Uesugi had only 15,000 troops to defend the castle, but clan head Ujiyasu Hojo inspired the garrison with his presence.
The Hojo Clan, since they faced eight-to-one chances, had to develop a plan to defeat the enemy. They decided on a coordinated night attack between the garrison and the reinforcements, with the samurai and Yari Ashigaru abandoning their heavy armor.
First, Ujiyasu Hojo lured out the Nagao clan's troops, killing Norikage Nagao and Norinaga Nagao. After doing this, he made moves for the southeastern garrison, held by Norimasa Uesugi. Norimasa, the clan's daimyo, was routed and wounded by the Hojo, who let out a warcry that confused the Uesugi, and infighting began. This confusion aided Tsunashige Hojo, who was escorted out of the castle after Sukataka Ota fled from besieging the castle. Tsunashige was sent to annex Koga while Ujiyasu faced reinforcements from the Takeda and the Imagawa, who allied to the Uesugi.
Tsunashige left the battlefield, and was relieved by Ujiyasu. Ujiyasu led a counterattack against the Takeda and Imagawa, and let the Uesugi scrape up the last of the dissidents in their cause, led by Noriyori Takada. After this happened, the Hojo troops stormed the Uesugi main camp and Tomosada was killed in the scuffle. This victory not only advanced Ujiyasu's prestiege as a warrior, but led to the near-extinction of the Uesugi.