A Tachi (太刀) is a classical Japanese curved long sword predating the katana that is worn suspended edge-down from cords on the belt. It was developed for mounted combat (samurai on horseback) and used primarily before the 15th–16th century. The katana later evolved from the tachi.
⚔️ Tachi vs Katana
Feature Tachi Katana
How it’s worn Edge down Edge up
Position Hung from cords Inserted through obi
Purpose Cavalry warfare Infantry combat
Curvature Deeper curve Slightly straighter
Length Usually longer Slightly shorter
Usage period Heian–Muromachi Muromachi onward
In koryū usage, a tachi refers to the actual sword type but it can also refer to long sword usage in paired kata systems (kumitachi).
Related Terms
Kodachi (小太刀) – Short sword; literally “small tachi”.
Kumitachi (組太刀) – Pre-arranged paired long-sword forms in koryū.
Nodachi / Ōdachi (野太刀 / 大太刀) – Very large battlefield swords.
Tachiuchi (太刀打ち) — sword striking exchanges
Tachi-koshirae (太刀拵え) – Mountings specifically designed for a tachi.
Tachi-obi (太刀帯) – Belt or suspension system for wearing the sword.
Tachiuchi (太刀打ち) – Paired sword fighting between two long swords.
Tachi no Kurai (太刀之位) – A concept/system of sword positioning in Yagyū Shinkage-ryū.
Tachisuji (太刀筋) – “Line of the sword” — the angle/path of a proper cut.
Tachiai / Tachi-ai (立会) – Standing encounter or formal duel engagement.
Tachi-kamae (太刀構え) – Long-sword guard/stance.
Tachi-giri (太刀切り) – Long-sword cutting.
Tachi-otoshi (太刀落とし) – Dropping / deflecting an opponent’s sword.
Tachi-mei (太刀銘) – Signature carved on a tachi.
Tachikiri-mono (太刀切物) – Objects cut in sword-testing trials.
Translation
太 = great / large
刀 = sword
太刀 Tachi is literally “great sword.”
There are two common meanings: 1. Tachi as the physical sword type and 2. Tachi as a term referring to long-sword techniques in traditional martial arts (versus kodachi / short sword techniques).
Tachi 太刀 is not to be confused with another Tachi 立ち, meaning standing, used to describe postures.
