The Minato Disturbance refers to a series of conflicts occurring during the Sengoku period in the environs of Minato Castle in Dewa Province in Tenbun 13 (1544), Genki 1 (1570), and Tenshō 17 (1589). The conflicts were waged between two branches of the Andō clan (ancestors of the Akita clan) known as the Hiyama-Andō and the Minato-Andō families and, to a degree, kokujin, or provincial landowners, from the area.
There is a lack of primary sources and descriptions are generally based on materials such as military chronicles compiled in later eras, so many details remain uncertain. Previously, the events were deemed to have occurred in 1570 and 1589, but, according to recent theories from local historians, the Minato Disturbance occurred on three occasions. There are indications that the first and second disturbances were mixed together when recorded. The third disturbance occurring in 1589 is also referred to as the Battle of Minato.
During the Sengoku period, the Andō family of northern Dewa was split into two branches – the Hiyama-Andō based at Hiyama Castle and the Minato-Andō based at Tsuchizaki-Minato Castle. In the Kamakura period, among the families based in the Tsugaru region, at a relatively early time, the Minato-Andō headed south and took control of the area around the mouth of the Omono River. Meanwhile, the Hiyama-Andō remained in Tsugaru into the Muromachi period, but, owing to an invasion by the Nanbu clan, temporarily fled north to the Ezo territories and then came south again to settle near the mouth of the Yoneshiro River. The Hiyama-Andō appeared to be the main branch of the family but, until the Sengoku period, there were no notable conflicts.
In the Tenbun era (1532 to 1555), momentum increased for the two families to reunite. These developments, however, were accompanied by a series of disturbances. Although the two families were in conflict, as a visible step toward their reconciliation, Andō Kiyosue (the seventh head of the Hiyama-Andō) received as his formal wife the daughter of Andō Takasue (the seventh head of the Minato-Andō). Andō Chikasue was born as the son of Kiyosue and his wife. Later, the bloodline of the Minato-Andō came to an end so Chikasue unified the two branches of the Andō clan.
There are differing views as to whether the reunification of the family was peaceful or done forcefully by Chikasue. In particular, when Takasue died in 1551, the Minato-Andō adopted Chikasue’s younger brother, Andō Shigesue, to be the successor to Takasue. Around 1579, however, after Shigesue died, Shigesue’s orphan, Andō Takasue, was still in his youth so Chikasue served as his guardian and thereby became the de facto head of both branches of the family. Originally, the Minato-Andō permitted daimyō and kokujin, or provincial landowners, from the upstream Omono River Basin to pay a low rate for use of the harbor. Once Chikasue exercised authority over this commerce, the Andō attempted to strengthen their control over the kokujin, who, in turn, resisted. This tension between the kokujin and the ruling Andō clan was manifested, in particular, in the Second Minato Disturbance. The First Minato Disturbance and the Third Minato Disturbance were rooted in tensions between the two branches of the family – the Hiyama-Andō and the Minato-Andō.
Andō Takasue, the seventh head of the Minato-Andō, did not have a natural son. His younger brother, Andō Tomochika, had a son named Andō Tomosue. Takasue adopted Tomosue as a successor. In 1544, it is surmised that Tomosue joined with his uncle, Wakimoto Yukisue, to fight against the Hiyama-Andō clan, but the details are uncertain. Tomosue died early. Thereafter, Takasue then adopted Andō Kiyosue’s second son, Andō Harusue. This was significant because Kiyosue was the seventh head of the opposing Hiyama-Andō clan. After the adoption, Takasue had Harusue change his name to Tomosue and welcomed him as the eighth head of the Minato-Andō. Takasue entered the priesthood, adopting the monk’s name of Kōkaku or Tessen-an. Tomosue, however, died prematurely, so he returned to secular life, changed his name back to Takasue, and became the ninth head of the family.
In 1570, Shigesue obeyed the wishes of his older brother, Chikasue, by imposing trade controls on the territory of the Toshima clan who were retainers of the Hiyama-Andō. Toshima Kyūshin then joined with kokujin in the environs of Minato Castle including 下刈 Ukyō, Kawajiri Nakatsukasa, and the Onodera and Tozawa clans of Senboku to launch a rebellion known as the Second Minato Disturbance. The foes engaged in violent clashes on Mount Suiko. With the assistance of Chikasue, however, the rebellion was finally suppressed after two years of conflict. Thereafter, Kyūshin relied upon his father-in-law in the Nikaho clan to escape. In 1579, he was pardoned of his crimes by Chikasue and returned to his position as the lord of Toshima Castle. According to one theory, after the event, the entire area of the Akita District came under the command of Chikasue while Shigesue moved to Toshima Castle.
The Daihōji clan demonstrated support for the Toshima by marching to the Yuri District situated along the coastline. In this series of conflicts, with the benefit of the self-destruction of Daihōji Yoshiuji (a daimyō and the seventeenth head of the Daihōji clan), the Andō family prevailed while a majority of the Yuri District came under the control of Chikasue. At this time, the Andō forces crossed over Mount Misaki and invaded Sakata. Meanwhile, in the Hinai area, Chikasue relied upon Asari Katsuyori to murder Kakizaki Yoshihiro. This enabled him to nearly unify the northern coastline of Dewa. He then marched inland with the aim of challenging the Tozawa clan for control over the Omono River Basin.
While maintaining his status as a sengoku daimyō, in 1587, Chikasue died of illness while on deployment along the Yodo River in Senboku in a conflict against Tozawa Moriyasu, the lord of Kakunodate Castle. This caused a loss of equilibrium among the competing powers in the region.
After Chikasue was succeeded by his son, Akita Sanesue, Andō Michisue (Toshima Michisue) advocated for the restoration of the Minato-Andō clan. He then joined with the Onodera and the Tozawa clans from the interior who sought to secure coastal areas along the Sea of Japan, and the Nanbu clan from northern Mutsu Province, and, in the second month of 1589, launched a rebellion against Sanesue known as the Third Minato Disturbance. According to some sources, this occurred in 1588.
The Toshima forces backing Michisue temporarily captured Minato Castle and then brought together kokujin such as the Yatsuyanagi and Nagai clans from across the Akita District and threatened Sanesue, forcing him to hole-up in Hiyama Castle. Michisue’s army greatly outnumbered Sanesue and his garrison defending the castle with a stockpile of only 300 arquebuses. Sanesue’s main force was comprised of members of the Hiyama group from the Hiyama District, members of the Hinai group including the Yoshinari clan from the Ani River Basin and the Asari clan from the Yoneshiro River Basin, and members of the Minato group who had moved from Minato to Hiyama. The siege of the castle extended over five months, but, owing to an invasion by the Nanbu clan of the Hinai District in northern Dewa, the opponents reached a provisional settlement. Taking advantage of this pause, members of the Twelve Heads of Yuri including the Akōzu and Hanegawa clans joined the contest on the side of Sanesue by attacking Minato Castle. Caught in a pincer attack, the Toshima forces were decimated while Minato Castle fell again to Sanesue. Surviving elements of the Toshima forces prevailed in the Battle of Terauchi but, despite striking back, later dispersed after Michisue fled in defeat.
Later, following the Battle of Minenoyama against the allied armies of the Tozawa and Onodera, the two sides settled and Sanesue placed the Akita District and surroundings under his firm command. Michisue fled to the protection of the Nanbu clan and became one of their retainers. This conflict was regarded by Toyotomi Hideyoshi as a violation of the order for daimyō not to engage in conflicts with one another over issues of territory or succession. Nevertheless, through the offices of Ishida Mitsunari, Sanesue was permitted to maintain his position and receive official recognition of his rights to his landholdings of 52,000 koku in the Akita District of Dewa. Among the territory seized, 25,000 koku was transferred to the direct jurisdiction of the Toyotomi while Sanesue served as their representative. Meanwhile, in exchange for joining the Conquest of Odawara, Michisue, accompanied by Nanbu Nobunao, requested the revival of his family name, but his service was declined by Mashita Nagamori. Sanesue moved his base to Minato Castle, changed his surname from Andō to Akita, and adopted the name of Akita Jōnosuke.