The nagamaki (長巻 "long wrapping") is a derivative of the naginata (長刀 "long sword") with a longer blade (from 70 to 80 centimeters, similar to that of a katana) which is mounted on a shorter pole (100 to 120 centimeters). The overall length of a nagamaki will be the same as the overall length of a naginata for a specific person, only the ratio of blade to pole is altered. Another difference is that nagamaki may have a yokote (when speaking of blades, a transverse ridge between the blade and the point) like a katana while naginata do not. In fact, the blades from old katana were often re-purposed for use on the service end of nagamaki. As for the name, the much longer shaft on a naginata is never wrapped, whereas a nagamaki has wrapping on the grip (tsuka ito), like a sword.
Nagamaki were used primarily during the Kamakura (1182-1333),
Nanbokucho (1334-1392) and early Muromachi (1392-1573) eras by foot soldiers. The original purpose of the weapons was anti-cavalry, the nagamaki-naginata was used to cut off the legs of enemy horses. This would greatly even the odds, since archers (the heavy artillery of the day) who are no longer on horseback are much more vulnerable.
Nagamaki is not to be confused with negimaki (beef wrapped around scallions grilled with teriyaki sauce).
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