Nanbu Nobunao

Who They Were

Nanbu Nobunao (南部信直; 1 April 1546 – 22 November 1599) was a Sengoku period samurai and daimyō, and the 26th hereditary chieftain of the Nanbu clan. He held the courtesy title Daizen Daibu and the Court rank of Junior Fourth Rank, Lower Grade. Nobunao was born at Ikatai Castle in what is now the town of Iwate, the second son of Nanbu Masayasu, the 22nd chieftain of the clan.

Life and Career

In 1565, Nobunao was adopted by his cousin Nanbu Harumasa, the 24th chieftain, to serve as heir, and took up residence at Sannohe Castle. In 1566 and 1568, he successfully defended the clan’s territory in Kazuno against incursions by forces under Andō Chikasue.

In 1570, a concubine of Harumasa gave birth to a biological son, Nanbu Harutsugu. Nobunao remained heir, but in 1576 his wife—Harumasa’s daughter—died. Fearing his position had been fatally undermined, Nobunao formally renounced his status as heir and went into hiding, taking refuge at Ne Castle with the Hachinohe branch of the clan. In 1582, Harumasa died and Harutsugu became the 25th chieftain. Harutsugu then died within a year, possibly of smallpox, although it was widely rumoured that Nobunao had him assassinated. With Harutsugu’s death, the various branches of the Nanbu clan decided to make Nobunao the 26th chieftain. This decision was opposed by a faction led by Kunohe Masazane, a noted warrior who argued that his blood ties to the succession were stronger.

In 1590, during the Siege of Odawara, Nobunao led a force of 1,000 men, primarily from Sannohe and Hachinohe, and pledged fealty to Toyotomi Hideyoshi. In return, he was confirmed as daimyō of his existing holdings in northern Mutsu province, covering the districts of Nukanobu, Hei, Kazuno, Kuji, Iwate, Shiwa, and Tōno. However, because the Ōura clan had already pledged fealty to Hideyoshi before Nobunao, he was denied control over Tsugaru, which the Ōura had seized from the Nanbu in 1571. Hideyoshi subsequently sent a huge army to quell the Kunohe Rebellion, which secured Nobunao in his position. He was then awarded the additional territories of Hienuki and Waga as compensation for the loss of Tsugaru. Although his territory was vast geographically, it had an assessed kokudaka of only 100,000 koku, as much of the area was not suitable for growing rice.

In 1592, Hideyoshi ordered Nobunao to Nagoya in Hizen Province to provide 1,000 troops for the invasion of Korea. He and his forces were never given the order to cross over, and subsequently returned home. Nobunao relocated his seat from Sannohe Castle to the more central location of Morioka, and began work on Morioka Castle and its surrounding castle town in 1592. He did not live to see its completion, dying at Kunohe Castle in 1599.

Why They Matter

Nobunao secured the Nanbu clan’s position under the new national order of Toyotomi Hideyoshi at a moment when the clan’s internal succession disputes threatened to tear it apart. His decision to pledge fealty at Odawara in 1590, and his survival of the Kunohe Rebellion, allowed the Nanbu to retain control over a vast swath of northern Mutsu. His relocation of the clan seat to Morioka laid the groundwork for the Morioka Domain, which his son would govern under the Tokugawa shogunate.

The Name in Japanese

The name is written 南部信直.

• Kana reading: なんぶ のぶなお
• Romaji: Nanbu Nobunao

Character by character:

• 南 (なん, nan) — “south.” In the clan name 南部, it combines with the next character to mean “southern part.”
• 部 (ぶ, bu) — “part,” “section,” or “division.” Together, 南部 (Nanbu) literally means “southern region,” a reference to the clan’s origins in the southern portion of what is now Iwate Prefecture.
• 信 (のぶ, nobu) — “trust,” “faith,” or “belief.” This character is a common element in samurai names, often passed down through generations as a hereditary syllable.
• 直 (なお, nao) — “straight,” “direct,” or “honest.” In personal names, it frequently carries the sense of uprightness or integrity.

The given name 信直 (Nobunao) thus combines “trust” and “straightness,” a pairing typical of Sengoku-era warrior names that emphasised loyalty and moral rectitude. The surname 南部 is shared by the clan as a whole, while the given name distinguishes Nobunao from the many other Nanbu chieftains who bore the same surname.

Legacy

Nobunao was succeeded by his son, Nanbu Toshinao, who became the 1st daimyō of Morioka Domain under the Tokugawa shogunate. The Morioka Castle that Nobunao began in 1592 became the administrative heart of the domain, and the castle town he laid out grew into the modern city of Morioka. His confirmation as daimyō in 1590, despite the loss of Tsugaru, fixed the boundaries of Nanbu territory that would persist through the Edo period. The Kunohe Rebellion, which he survived with Hideyoshi’s military backing, marked the end of serious internal challenges to Nanbu authority.