Ōdachi

The odachi is a type of traditionally made Japanese sword used by the samurai class of feudal Japan, produced from the Kamakura period, 1185 to 1333, onward. These oversized blades, ranging from roughly 91 to 227 centimeters, grew popular as foot soldiers increasingly fought on the ground rather than on horseback, and their use peaked in the fourteenth century Nanboku-cho period before the weapon gradually gave way to spear and firearm tactics during the Sengoku period. Their great length made them impractical to wear at the waist, so warriors carried them on their backs or had servants transport them, and forging one demanded exceptional skill because heating so long a blade to a uniform temperature is far harder than for an ordinary sword. In the peaceful Edo period many odachi shifted from battlefield use to a ceremonial role as offerings to the kami at Shinto shrines. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/