Itabeoka Kōsetsusai
板部岡江雪斎
Diplomat-Monk Who Served Three Generations of the Later Hōjō, Remembered Through His Sword Kōsetsu Samonji
Description
Life
He is said to have been born in 1537 (by another account, 1536) as the son of Tanaka Yasuyuki, lord of Tanaka in Tagata District, Izu Province. He first became a Shingon Buddhist monk, but later entered the service of the Later Hōjō clan, returning to lay life under the succession name Itabeoka Yasuo, and served as scribe (yūhitsu) and council member (hyōjōshū) under three successive Hōjō lords: Ujiyasu, Ujimasa, and Ujinao.
Achievements as a Diplomat-Monk
Prized for his fine calligraphy and eloquence, he was heavily relied upon as the Hōjō clan's channel for external negotiations. He traveled to negotiate with the Takeda and Oda clans, and arranged the marriage between the clan head Ujinao and Tokugawa Ieyasu's daughter Tokuhime, serving as a linchpin of Hōjō diplomatic strategy. During the 1589 dispute over the arbitration of Numata territory, he worked to repair relations with Toyotomi Hideyoshi, though this ultimately failed to prevent the following year's campaign against Odawara.
After the Siege of Odawara
At the surrender of Odawara Castle in 1590, he served as an envoy in the peace negotiations. After the fall of the Hōjō clan, he was taken into Hideyoshi's service and made a member of his companion circle (otogishū); after Hideyoshi's death he drew close to Tokugawa Ieyasu and is said to have accompanied him at the Battle of Sekigahara. He died in 1609.
Connection to Swords
Kōsetsusai's prized sword, known as "Kōsetsu Samonji," is attributed to the Nanboku-chō-period swordsmith Samonji. It was presented to Tokugawa Ieyasu upon the fall of the Hōjō clan, and after Ieyasu gave it to Tokugawa Yorinobu, founder of the Kishū Tokugawa house, it was handed down as a treasure of that house. It is today designated a National Treasure and held by the Fukuyama Museum of Art in Fukuyama, Hiroshima Prefecture.
Later Reputation
Kōsetsusai is known as a cultured figure versed in the tea ceremony and waka poetry, and is regarded as a forerunner of the diplomat-bureaucrat type of warrior, distinct from purely martial figures. His prized sword Kōsetsu Samonji survives today as a National Treasure, standing as a symbol of the Hōjō clan's diplomacy and refinement in the closing years of the Sengoku period.
Notable Swords
- Kōsetsu Samonji