A castle associated with the "Osaki Ikki" uprising of 1590 (Tensho 18). Following Toyotomi Hideyoshi's Oshu Shioki (pacification of the Tohoku region), former retainers of the Osaki clan allied with Date Masamune and rose in revolt, barricading themselves in Sanuma Castle. Masamune was reprimanded by Hideyoshi on suspicion of having supported the uprising and faced considerable difficulty in justi…

The origins of Sanuma Castle are believed to trace back to a medieval stronghold established along the Kitakami River under the control of the Osaki clan. The castle's history is clearly documented from 1590, when former retainers of the Osaki clan, acting in concert with Date Masamune, rose in rebe…