 The Narita clan changed their allegiance to the Odawara Hōjō clan following the defeat of the Uesugi clan at the Siege of Kawagoe Castle in 1546.Fourteen years later Uesugi Kenshin, the "daimyō" of the Uesugi clan, invaded the area in support of Uesugi Norimasa (the "Shōgun"'s deputy or Kanto kanrei).This forced Narita Nagayasu, the Castellan of Oshi Castle to sever his ties to the Odawara Hōjō.