Mizuno Katsushige

Mizuno Katsunari (1564-1651) was a military commander who was the cousin of Tokugawa Ieyasu and one of the strongest warriors of the Sengoku period, known by the nicknames "Demon of Hyuga" and "Gambler." In his youth, he led a wandering life apart from his lord, undergoing martial training across various regions, and became renowned as the archetypal Sengoku "roving warrior."

Katsunari was born in 1564 in Mikawa Province (present-day Aichi Prefecture) as the son of Mizuno Tadashige. His father Tadashige's elder sister was Tokugawa Ieyasu's biological mother, the Lady Ōyodo; thus, Katsunari and Ieyasu were cousins. In his youth, after a violent quarrel with his father, he fled and wandered through Kyushu, Chugoku, Shikoku, and Kinki, moving from battlefield to battlefield in pursuit of "first spear" and "first to take a head." The practical combat experience and swordsmanship cultivated during this period of wandering became the source of his martial prowess—so formidable that he was feared as the "Demon of Hyuga."

At the Battle of Sekigahara (1600), he served the Eastern Army (Tokugawa forces) and distinguished himself alongside Fukushima Masanori. Through this achievement, he was elevated to daimyo rank and eventually became the lord of Fukuyama Domain in Bingo Province with 100,000 koku. During the Siege of Osaka (1614-1615), he also played a major role, reportedly still wielding his spear well beyond the age of 70.

In relation to swords, Katsunari was renowned as a master of the Japanese blade. During his years as a wandering warrior, he refined his swordsmanship across various regions, particularly mastering the techniques of the Itto-ryu (One Sword School). The swords he possessed are known as "Mizuno Katsunari's famous blades," cherished as practical battle swords that accompanied him through the battlefields of Sekigahara and the Siege of Osaka. As lord of Fukuyama Domain, he also protected the swordsmithing industry of Bingo Province, contributing to the flourishing of the regional sword-maker culture.

Katsunari died in 1651 at the advanced age of 88, exemplifying the life of a warrior who survived the transition from the turbulent Sengoku era to the peaceful Edo period. His dramatic life story continues to serve as material for numerous historical novels and NHK historical dramas today.