Ii Naomasa
In 1590, when Toyotomi Hideyoshi began his campaign against the Hōjō, he sent a large army along the Nakasendō against Minowa Castle. However, the garrison at the castle surrendered without a fight. Subsequently, the Kantō region was awarded to Tokugawa Ieyasu, who assigned Ii Naomasa as castellan. Ii Naomasa significantly expanded the castle and dug deep and wide dry moats and replaced earthen ramparts with stone walls along the main route into the castle. In 1598, he built Takasaki Castle and relocated his seat there. Minowa Castle was abandoned and allowed to fall into ruin.