tachi

The tachi is a type of Japanese sword recognized for its long, curved, single-edged blade and distinctive mounting. It was the primary battlefield sword of the samurai from the late Heian period into the Muromachi period, and it predates the later katana. Typical blade lengths (nagasa) range from about 60 to 80 centimeters, with some longer specimens. The tachi is designed for slashing from horseback and is traditionally worn edge-down, suspended from a belt by cords attached to the scabbard.

Design and construction features include a pronounced curvature and a single edge, with the temper line (hamon) varying by school. The sword is paired with a long scabbard (saya) and illustrates mounting conventions that accommodated mounted use. The tang (nakago) and overall balance were suited to rapid, downward cuts while riding, and the scabbard fittings often included cords and knobs (kurikata) used to tie the weapon securely to the belt.

Historically, the tachi emerged in the early medieval period and became the standard long sword for mounted samurai. In the later 16th century, as warfare shifted toward infantry and different fighting styles, the shorter uchigatana gained prominence as the primary belt-worn sword, leading to a decline in new tachi production. Nonetheless, historical tachi remain central to studies of Japanese sword-making and are frequently preserved in museums as important examples of traditional nihon-to craftsmanship.

Modern production continues in the traditional style, and tachi remain a subject of scholarly study, ceremonial use, and martial arts practice, alongside other Japanese blade types such as the katana, wakizashi, and tantos.