The Waga-Hienuki Uprising occurred in 1590 as a revolt led by kokujin, or landowners, in Mutsu Province opposed to the reallocation of territories, land surveys, and other measures taken by the Toyotomi administration in the Oushū Retribution.
In 1590, Toyotomi Hideyoshi raised an army for the Conquest of Odawara. Landowners and daimyō from the Kantō and Ouu regions deployed one after another to Odawara to join the Toyotomi army, but those who did not join, including Yūki Yoshichika, Ishikawa Akimitsu, Esashi Shigetsune, Kasai Harunobu, Ōsaki Yoshitaka, Waga Yoshitada, and Hienuki Hirotada (Shigetsuna), witnessed their territories seized and were expelled from their castles during the subsequent Oushū Retribution.
After the ouster of the Waga clan from their base at Toyagasaki Castle (later known as Hanamaki Castle), Asano Nagamasa (a magistrate of Hideyoshi) entered and ordered commanders for the Oushū army to advance to the environs of Hiraizumi to suppress several castles in the territory of the Waga clan. Retainers of Nagamasa were stationed on behalf of the Toyotomi and progress was made toward establishing a new system. After conducting a land survey, district governors and officials remained while the Oushū Retribution army withdrew.
Break-out of hostilities
Former retainers of fallen daimyō from the Ōsaki, the Kasai, and the Kashiyama from the Iwasa District along with local peasants harbored grievances toward the Toyotomi over the land surveys. Soon after the withdrawal of the Toyotomi army, in the tenth month, these groups launched uprisings across their territories, killed a bushō sent by Hideyoshi named Kimura Yoshikiyo, and wielded their power. In tandem with these events known as the Kasai-Ōsaki Uprising, Waga Yoshitada and Hienuki Hirotada launched their own rebellions in the Waga and Hienuki districts of Mutsu Province.
On 10/23 (or 10/28), the ikki forces launched a surprise attack against Asano Nagamasa and Gotō Hanshichi who were located in Futago Castle, the former base of the Waga clan and recovered the former territory of the Waga. Riding on the momentum, over 2,000 local forces proceeded to surround Toyagasaki Castle. These forces were, until shortly prior, conscripted soldiers much more experienced in battle than the local peasants. Meanwhile, the official in the castle, Asano Shigeyoshi, had at his disposal a garrison of only 100 mounted soldiers and 150 foot soldiers. The castle, however, was protected by natural features making an assault difficult.
Hideyoshi had Nanbu Nobunao, a daimyō in northern Mutsu whose land rights had been recognized during the reformation, gather forces at Kozukata Castle (later known as Morioka Castle), while Nobunao himself rushed with 500 mounted soldiers to Toyagasaki Castle to reinforce the besieged forces. On 11/7, Nobunao and his soldiers attacked the enemy forces and broke the siege. The Nanbu army at once entered Toyagasaki Castle but, with the approach of the winter season, determined that it would be difficult to hold-out in the castle so they abandoned the site and withdrew along with Asano Shigeyoshi and the others to the base of the Nanbu clan at Sannohe Castle. As a result, the former territory of the Hienuki clan including Toyagasaki Castle fell to the ikki forces.
In this manner, the district governors and officials sent to Ouu on behalf of the Toyotomi administration were, before long, expelled by the military forces of the former landowners.
Return of the Toyotomi army
To suppress these large-scale uprisings and the Revolt of Kunohe Masazane that erupted in the territory of the Nanbu, on 6/20 of 1591, Hideyoshi formed an army to reinforce the reformation in the Oushū Region. At the entrance to Shirokawa, Tokugawa Ieyasu joined a contingent of 30,000 soldiers led by Toyotomi Hidetsugu as the commander-in-chief, while Uesugi Kagakatsu and Ōtani Yoshitsugu were assigned to the entrance to Senboku, Maeda Toshiie and Maeda Toshinaga to Tsugaru, and Ishida Mitsunari, Satake Yoshishige, and Utsunomiya Kunitsuna to the entrance to Sōma. Date Masamune, Mogami Yoshiaki, Onodera Yoshimichi, Tozawa Mitsumori, Akita Sanesue, and Tsugaru Tamenobu were instructed to serve under the command of these generals. This army invaded Ouu and, after converging with Gamō Ujisato and Asano Nagamasa, subdued uprisings while marching north.
Despite putting-up stiff resistance, the Waga clan was suppressed by the invading army. While attempting to flee, Waga Yoshitada was killed by local citizens. Thereafter, the territory was granted to Nanbu Nobunao and the Waga and Hienuki clans were decimated. Resentful of these developments, Waga Tadachika (the son of Waga Yoshitada) later launched another rebellion known as the Iwasaki Uprising.
Nanbu Nobunao assigned Kita Hidechika to serve as the chamberlain of a fief of 8,000 koku from the Waga and Hienuki clans. Hidechika then changed the name of Toyagasaki Castle to Hanamaki Castle.