Date and Mogami Fight the Northern Campaign of 1600

Ieyasu’s campaign against Uesugi Kagekatsu drew Date Masamune into fighting along the northern frontier. Masamune attacked and occupied Shiroishi, while the Uesugi also faced Mogami Yoshiaki in Dewa. These operations took place far from the eventual field battle in Mino.

Naoe Kanetsugu led Uesugi forces toward Yamagata and attacked the Mogami stronghold at Hasedō. Its defenders held out, and Date forces supported the Mogami side. When news arrived that the western coalition had lost at Sekigahara, Naoe withdrew. Resistance at Hasedō had delayed his advance before that news changed the wider military situation.

A surviving Ieyasu memorandum dated the twenty-second day of the eighth Japanese month promised restoration of former lands then held by the Uesugi. Added to Date’s existing holdings, they would have exceeded a million koku in assessed rice yield, giving the document its familiar name. The actual settlement added only Katta, the district containing Shiroishi. Masamune’s participation gained territory, but the anticipated larger restoration did not follow. Northern towns and castles had changed hands through their own fighting, and the eventual settlement depended on decisions made after Ieyasu’s wider victory.