Japanese sword evolution

Japanese katana production can be divided into specific time periods:

1. Jōkotō (ancient swords, until around 900 A.D.)

2. Kotō (old swords from around 900–1596)

3. Shintō (new swords 1596–1780)

4. Shinshintō (newer swords 1781–1876)

5. Gendaitō (modern swords 1876–1945)

6. Shinsakutō (newly made swords 1953–present)