Tsugaru Tamenobu

Tsugaru Tamenobu (1550–1607) was a daimyo who achieved independence from the Nanbu clan's rule over the Tsugaru region (present-day western Aomori Prefecture) and established the foundation of Tsugaru Domain. He was known as a "cunning warlord" who wielded both strategic acumen and military prowess to achieve independence from the main Nanbu house, while also serving as a politician who sought his clan's survival through skillful diplomacy with the Toyotomi regime.

Tamenobu was originally the head of the Ōura clan, a cadet house under the Nanbu clan, but around 1571 he began gradually seeking independence from the Nanbu. He expanded his power by successively conquering neighboring castles, and through campaigns such as the conquest of Nanaoka Castle in Tenshō 6 (1578), he extended his influence and solidified de facto independence with Ōura Castle as his base. During this period, there are numerous records of his use of stratagems and ingenious tactics, which formed the basis of his reputation as a "cunning warlord."

Following Toyotomi Hideyoshi's unification of Japan, Tamenobu quickly drew close to the Toyotomi regime. During the 1590 Siege of Odawara, he participated under Hideyoshi's command, and through this he had his lands confirmed. At this time, he changed his clan name from "Ōura" to "Tsugaru," establishing independent status as the Tsugaru clan. In the Battle of Sekigahara (1600), he sided early with the Tokugawa and advanced favorable post-war arrangements, laying the foundation for Tsugaru Domain's survival and development.

Regarding swords, Tamenobu is said to have favored blades forged by swordsmiths of northeastern Japan in the Tsugaru and Nanbu regions. The Tsugaru region was known since ancient times as an iron-producing area, and swordsmiths using locally sourced iron existed in the region. The swords collected by Tamenobu are transmitted as treasures of Tsugaru Domain, forming an important aspect of northeastern Japanese sword culture.