Sakai Tadatsugu

Sakai Tadatsugu (1527–1596) was a warrior from Mikawa Province (present-day eastern Aichi Prefecture) and one of the most trusted retainers of Tokugawa Ieyasu. Known as the foremost of the "Four Heavenly Kings of Tokugawa" (Sakai Tadatsugu, Honda Tadakatsu, Sakakibara Yasumasa, and Ii Naomasa), he supported Ieyasu over many years. Celebrated as a distinguished general combining valor and strategic acumen, he excelled in numerous battles.

Tadatsugu was born in 1527 as the second son of Sakai Masachika, a local landowner in Mikawa Province. From his youth he served the Tokugawa household (then the Matsudaira family), and at the Battle of Okehazama in 1560, he demonstrated his talents early by successfully executing a supply mission to Ōtaka Castle against Imagawa forces. At the Battle of Anegawa in 1570, he turned the tide by striking the flank of the combined Asai-Asakura forces.

At the Battle of Nagashino in 1575, his achievement in successfully executing a surprise attack on the Tobi-gasuzan fortress of the Takeda army, thereby determining the course of the battle, is especially noteworthy. In this engagement, Tadatsugu led elite forces in a sudden assault on a key Takeda position, contributing to the great victory of the combined Tokugawa-Oda forces at Shitaragahara. Following the Odawara Campaign of 1590, when Ieyasu was relocated to the Kantō region, Tadatsugu was granted a residence in Kyoto (Sakurai district) by Hideyoshi after his retirement, where he lived in seclusion, and died in 1596 at the age of 70.

In relation to Japanese swords, Tadatsugu is said to have cherished a tachi called "Inoshishi-giri" (Wild Boar Cutter), which bears a gold inlay inscription and is housed in the Taidō Museum collection. This blade is reportedly named after an anecdote of cleaving a wild boar in a single stroke, and is passed down as a sword symbolizing the valor of Mikawa warriors. He is also said to have possessed several swords presented by Ieyasu, and the blades inherited by the Sakai family were carefully preserved for posterity. The beloved swords of Tadatsugu, who embodied the steadfast spirit of Mikawa warriors, are still spoken of today as precious testimony to the bond between Japanese swords and warriors in the Sengoku period.