was key to the
Mōri clan's defense of their inner provinces against the encroachment of
Oda Nobunaga. In late 1580, as part of his campaign to extend Nobunaga's domain to the west,
Hashiba Hideyoshi moved north from his new base in
Harima and by 1581 entered
Inaba province on the Sea of Japan wherein his forces encountered
Tottori castle. The
yamashiro (mountain) castle, built into the mountain itself, was owned by the
Yamana clan under
Yamana Toyokuni, but had passed to the Mori and was guarded by their retainer,
Kikkawa Tsuneie. Hideyoshi made efforts to negotiate with Tsuneie, but the Mori retainer was resolved to hold onto the castle and keep it from falling into Oda hands. ==Siege==