The production of swords in Japan is divided into time periods:Jōkotō (上古刀 "ancient swords", until around 900 A.D.)
Kotō (古刀"old swords" from around 900–1596)
Shintō (新刀 "new swords" 1596–1780)
Shinshintō (新々刀 "new new swords" 1781–1876)
Gendaitō (現代刀 "modern swords" 1876–1945)[5]
Shinsakutō (新作刀 "newly made swords" 1953–present)[6]
A range of Japanese blade types, from left to right: naginata, ken, tantō, uchigatana and tachi (not to scale).
In modern times the most commonly known type of Japanese sword is the Shinogi-Zukuri katana, which is a single-edged and usually curved longswordtraditionally worn by samurai from the 15th century onwards.[7] Other types of Japanese swords include: tsurugi or ken, which is a double-edged sword;[8] ōdachi, tachi, which are older styles of a very long single-edged sword; wakizashi, a medium-sized sword and tantō which is an even smaller knife-sized sword. Naginata and yari despite being polearms are still considered to be swords.[1][2]
Japanese swords are still commonly seen today, antique and modern forged swords can easily be found and purchased. Modern, authentic nihontō are made by a few hundred swordsmiths. Many examples can be seen at an annual competition hosted by the All Japan Swordsmith Association,[9] under the auspices of the Nihontō Bunka Shinkō Kyōkai (Society for the promotion of Japanese Sword Culture).[10]
Western historians have said that Japanese katana were among the finest cutting weapons in world military history.