Itagaki Nobukata served as a bushō during the Sengoku period.  He served as a retainer of Takeda Nobutora and, later, Takeda Harunobu (Shingen).  Nobukata is counted among the Twenty-Four Generals of the Takeda.  He is also one of the Four Guardian Kings of the Takeda.

Nobukata’s original home is surmised to have been in the Ozo township in the Yamanashi District of Kai Province.  According to records, in 1547, he donated his landholdings in the township to the Mukaidake hermitage.

From the era of Takeda Nobutora, a sengoku daimyō and the fifteenth head of the Takeda clan, Nobukata served as a veteran general for the Takeda.  He further served as a mentor for Nobutora’s lineal heir, Harunobu.  In 1540, during an invasion by Nobutora of the Saku District of Shinano Province, Nobukata felled several tens of enemy soldiers.

In 1541, Nobutora was ousted from Suruga Province by Harunobu.  After Harunobu garnered the headship of the clan, Nobukata and Amari Torayasu were appointed to the highest roles in the Takeda family.  Nobukata became the head of the Takeda band of retainers.  Leading soldiers from Suwa, he served valorously in battles to conquer Shinano.  During the Battle of Uedahara against Murakami Yoshikiyo, Nobukata served in the vanguard forces and, at the outset of hostilities, gained the advantage but, during a counterattack, was killed.

In the seventh month of 1542, Harunobu joined with Takatō Yoritsugu to invade the Suwa District of Shinano and force the surrender of Suwa Yorishige who was then incarcerated at the Tōkō Temple in the Itagaki township.  On 7/21, Yorishige and his younger brother, Suwa Yoritaka, killed themselves.  Desiring a leadership position in the Suwa family, in the ninth month, Yoritsugu joined with Fujisawa Yorichika to invade the Suwa District and toppled Uehara Castle.  Harunobu quickly sent reinforcements with Nobukata in the vanguard to defeat Yoritsugu at the Battle of Ankokuji.

Following Harunobu’s decimation of the Suwa clan, including the ouster of Yoritsugu and the surrender of Fujisawa Yorichika, in the fourth month of 1543, Harunobu appointed Nobukata as the governor of the Suwa District and chamberlain of Uehara Castle.  In the fifth month, upon the completion of preparations, Nobukata entered the Suwa District.  There are documents with Nobukata’s seal pertaining to land allocations in the Suwa and Saku districts with dates preceding his appointment as district governor.  These, however, are presumed to be provisional guarantees for the official recognition of rights.

On 4/17 of Tenbun 14 (1545), following the surrender of Yoritsugu, Harunobu captured Takatō Castle and Yoritsugu was sent to serve in Kōfu.  This event is known as the Battle of Takatō.  Next, Harunobu assaulted Fukuyo Castle defended by Fujisawa Yorichika who had betrayed Harunobu again, but Yorichika joined forces with Ogasawara Nagatoki of Shinano to resist.  Nobukata proceeded to attack Ryūgasaki Castle which was aligned with the Fujisawa and Ogasawara clans and, after becoming isolated, Yorichika surrendered.

In the seventh month of 1547, Harunobu, together with Nobukata leading soldiers from Suwa, mounted an invasion with a large army into the Saku District and laid siege to Shiga Castle defended by Kasahara Kiyoshige.  Uesugi Norimasa, the deputy shōgun of the Kantō had Kanai Hidekage lead reinforcements from western Kōzuke there.  Harunobu then had Nobukata and Amari Torayasu form a detached division to intercept the enemy forces.  On 8/6, at the Battle of Otaihara, Nobukata crushed the army of the deputy shōgun of the Kantō, killing 14 or 15 commanders and 3,000 soldiers in a major victory.  Having lost the prospect of reinforcements, the defenders at Shiga Castle capitulated, allowing Harunobu to fully pacify the Saku District of Shinano.

In the second month of 1548, Harunobu deployed to the Chiisagata District with the aim of eliminating Murakami Yoshikiyo.  On 2/14, the Takeda army was defeated at the Battle of Uedahara and Nobukata, along with Amari Torayasu, Saima Kawachi-no-kami, and Hajikano Denemon were all killed in action.

After the demise of Nobukata, his lineal heir, Itagaki Nobunori, inherited the headship of the clan but was ousted from the Takeda family by Takeda Shingen for misconduct.  Later, he was murdered.  As a result, the Itagaki family was at once extinguished, but, the following year, Nobukata’s son-in-law, Sakyō-no-suke Nobuyasu from the Ozo clan, upon orders from Shingen, assumed the Itagaki surname and revived the Itagaki family under the name of Itagaki Noubyasu.  He then became a member of the Kai-Itagaki lineage and, after the decimation of the Takeda clan by the Oda in the third month of 1582, he served Sanada Masayuki, later becoming a retainer of the Kaga domain.  Among the descendants of Nobunori who were expelled from the Takeda family, Itagaki Taisuke served in the Boshin War which occurred in 1868 to 1869.

Anecdote

As Nobukata became older, he often acted impudently so Shingen admonished him in a waka, or classical poem.