Japanese Swordsmithing Craft

Timeline

1. c. 900–1185Yamashiro Province · KinkiCurved tachi forms appeared in the late Heian period; smithing employed folded hammering and quench heat treatment, establishing the technical foundation for the Japanese sword's distinctive hamon and curvature.
2. c. 1185–1333Bizen · Mino · Sagami · JapanFamous smiths such as Munemitsu and Masamune flourished in the Kamakura period; Bizen, Mino, Yamashiro, Sagami, and Harima formed regional smithing schools, with hamon quenching and clad-steel techniques reaching maturity.
3. 1491–1600Smithies across the Japanese archipelago · JapanWarring States warfare drove the katana (belt-worn sword) to replace the tachi as the mainstream; daimyō across the regions supported smiths in mass-producing weapons, with smithing techniques adapting to large-scale military needs while maintaining quality.
4. c. 1600Bizen · Banshū · JapanThe Edo shogunate controlled sword production through sword hunts and a smith-certification system; after the war, Japanese swords became art objects and cultural heritage; today's certified smiths still transmit folded hammering, hamon quenching, and polishing techniques.