The tachi is a
Japanese sword, normally wielded by
cavalry troops due to its length, which can be up to 4 feet in some cases. This sword differs from its direct ancestor, the
chokuto in that it has a narrow
blade with a single edge, and is highly
curved, apparently making it easier to draw from the
scabbard in one
motion. Tachis also usually had a metal band or hole in the butt of the
hilt called a
kashira so that a cord could be attached and wrapped around the
wrist
These blades were in common use between 800-1200 A.D., before a change in military tactics led to the creation of the katana