1600: Battle of Sekigahara and Postwar Reorganization
The Western Army led by Ishida Mitsunari and the Eastern Army led by Tokugawa Ieyasu confronted each other on a nationwide scale. In October, the Eastern Army won a decisive victory at Sekigahara. Preliminary battles were fought at Fushimi, Gifu, Otsu, Ueda, and in the northern provinces. After the war, massive reassignments, dispossessions, and rewards reshaped the daimyōs, solidifying Tokugawa supremacy.
Events this year
Month 8
With Hosokawa Tadaoki away on the Aizu campaign, Tango was attacked on Ishida Mitsunari's orders. Tadaoki's father Yusai held Tanabe Castle with about 500 men against a Western force said to number 15,000.
See this battle in detail →Sources 舞鶴市「舞鶴ふるさと発見館（郷土資料館）だより 令和4年9月号」
8/26
After Tokugawa Ieyasu marched toward Aizu, the Western Army surrounded Fushimi Castle, defended by Torii Mototada and his garrison.
See this battle in detail →Sources 京都市「都市史20 伏見城」／京都市「伏見区の歴史：安土桃山時代 秀吉が開いた城下町」／京都市文化財保護課「伏見城跡・指月城跡 現地説明会資料」
9/2
Tokugawa Ieyasu, on the march against Uesugi Kagekatsu at Aizu, received a messenger from Fushimi while encamped at Oyama and learned that Ishida Mitsunari had risen. At the council he called, the Aizu campaign was called off and the assembled lords are said to have turned west toward Sekigahara.
Sources 小山市「徳川家康ゆかりの地 小山評定と小山御殿」
9/8
Fushimi Castle fell and burned after the Western Army's assault, and its commander Torii Mototada and the garrison were killed.
9/30
Eastern Army commanders including Fukushima Masanori and Ikeda Terumasa captured Gifu Castle from Oda Hidenobu, securing the route through the Tōkaidō region.
See this battle in detail →Sources 岐阜観光コンベンション協会「岐阜城」／岐阜市「岐阜城跡」
Month 10
Tokugawa Hidetada's army attacked Ueda Castle, defended by Sanada Masayuki and Nobushige, but failed to take it and was delayed on its westward march.
See this battle in detail →Sources 上田市「上田城の歴史」／上田市「史跡上田城跡」
An Uesugi army under Naoe Kanetsugu invaded Mogami territory but failed to take Hasedo Castle and withdrew after news of Sekigahara.
See this battle in detail →Sources 山形市「長谷堂城跡」／山形城公式「歴代城主」／山形市地域教材「長谷堂合戦」
10/13
Kyogoku Takatsugu, who had gone over to the Eastern side, shut himself in Otsu Castle, and a Western force of some 15,000 under Mori Motoyasu and Tachibana Muneshige invested it.
See this battle in detail →Sources 大津市観光協会「びわ湖大津トラベルガイド 大津城ゆかりの地を歩く」／大津市観光協会「戦国の大津歴史舞台 大津と大津城」／大津市「大津城跡発掘調査報告書」
10/19
Otomo Yoshimune, seeking to recover his old domain, fought Kuroda Yoshitaka and Matsui Yasuyuki on the Ishigakibaru fan at Beppu. After heavy fighting from midday into the evening the Kuroda and Matsui side won and Yoshimune surrendered.
See this battle in detail →Sources 別府市「大河ドラマ『軍師官兵衛』ゆかりの石垣原合戦」
10/20
On the day before Sekigahara some 500 men under Shima Sakon and Gamo Bitchu left Ogaki Castle, crossed the Kuise river, provoked Nakamura Kazuhide's Eastern unit and broke it with an ambush - the one preliminary engagement the Western army won.
See this battle in detail →Sources 岐阜県観光公式サイト「杭瀬川古戦場」／大垣・西美濃観光ポータル「関ケ原合戦 決戦前夜 大垣城」
10/21
The decisive battle in Mino: Tokugawa Ieyasu’s Eastern Army defeats the Western Army.
See this battle in detail →Sources 岐阜県「岐阜関ケ原古戦場記念館」／関ケ原観光ガイド「決戦地」／関ケ原観光ガイド「開戦地」
Kyogoku Takatsugu gave up Otsu Castle on the same day as the battle at Sekigahara, so the large Western force besieging it never reached the decisive field.
See this battle in detail →Sources 大津市観光協会「びわ湖大津トラベルガイド 大津城ゆかりの地を歩く」／大津市観光協会「戦国の大津歴史舞台 大津と大津城」／大津市「大津城跡発掘調査報告書」
10/27
Ishida Mitsunari, who had fled from Sekigahara toward Mount Ibuki, was taken at Furuhashi in Omi by a search party under Tanaka Yoshimasa acting on Ieyasu's orders.
Sources 岐阜関ケ原古戦場記念館「石田三成コース」
11/6
Ishida Mitsunari was beheaded at Rokujogawara in Kyoto together with Konishi Yukinaga and Ankokuji Ekei. The execution of the three men at the centre of the Western army closed the first phase of the settlement after Sekigahara.
Sources 岐阜関ケ原古戦場記念館「石田三成コース」／岐阜関ケ原古戦場記念館「黒田長政コース」