After the establishment of the Tokugawa Shogunate, the Nanbu ruled the Shimokita Peninsula and the districts immediately to the south of it. The area to the west of the Nanbu's holdings and to the north of the lands held by the Akita clan were all controlled by the Tsugaru clan, from their capital at Hirosaki. Work on Hirosaki Castle was completed in 1611, replacing Horikoshi Castle as the Tsugaru clan's fortress. By 1631, the Tsugaru clan had solidified their control over their gains made during the Sengoku period. Mutsu Province was struck by the Great Tenmei famine between 1781 and 1789, due to lower than usual temperatures that were exacerbated by volcanic eruptions at Mount Iwaki, near the Tsugaru clan's capital, Hirosaki, between November 1782 and June 1783.