Although the "katana" has associations with "samurai sword" and represented the spiritual essence of the samurai class, this type of Japanese sword never saw primary use on the battlefield. Instead, the samurais of ancient and medieval Japan actually wielded several different types of swords. The katana was one type of samurai sword.
Origin of Samurai Swords
The samurai sword was first developed around the eighth century, in the Nara period. Prior to this, swords were imported from China. The swordsmith Amakuni and his son, according to legend, forged the first recognizably high-quality Japanese blades after the army returned from a battle with their swords broken or irreparably damaged. The next time war occurred, the samurai returned with Amakuni's swords in perfect condition.
The katana has a set of measurements that separate it from other samurai swords. Typically, a katana will measure 3 to 4 feet in total length, with the hilt taking up one-fourth of the total. The katana also has a characteristic curvature of 1 inch, though this can vary between swordsmiths.
Uses of the Katana
Because of the katana's curvature, it gave its wielder the ability to perform cuts from the draw. Once drawn, the katana was used as a slicing weapon on the battlefield to make devastating cuts to unarmored body parts such as the wrists. Samurai also used the katana in duels when they were outdoors. Indoors, they used the shorter companion sword, the wakizashi, because of etiquette and space limitations.
Misconceptions About the Katana
Although the katana has the reputation as the soul of the samurai and samurai were considered masters of the weapon, a look at history proves this false. According to Samurai Archives: Misconceptions of the Japanese Sword, the samurai never resorted to the katana as their primary weapon on the field. Instead, they used the bow in conjunction with cavalry because of their origin as mounted archers, the spear for infantry tactics to support archers on foot, the naginata to counter cavalry, and the arquebus, an early firearm. The katana and the wakizashi only saw use when the primary field weapons became unusable.
The Katana Today
The katana remains widespread in its appeal. Shinkendo, the combination of old and new Japanese sword arts, has become a popular martial art to learn the techniques in using the katana. The ownership of the samurai sword in Japan follows strict regulations--according to Guido Schiller on Nihonto Kanji Pages, any katana imported or owned in Japan must have accompanying registration proving its authenticity.