Meireki Era

The Meireki era (1655–1658) left an indelible mark on the history of Japanese swords through the Great Fire of Meireki (also known as the Furisode Fire), which broke out in the first month of Meireki 3 (1657) and consumed vast stretches of Edo, including the main keep of Edo Castle. According to estimates by sword researcher Itō Sanpei, roughly 100,000 swords were destroyed in the blaze. Among the losses were legendary blades such as the Uesugi Gō (once owned by Uesugi Kenshin), the Ōkuninuna handed down through the Ashikaga shogunal house, and the Hōchō Tōshirō held by the Tokugawa shogunate. Decades later, the Kyōhō Meibutsu-chō — a catalogue of Japan's 168 most celebrated swords compiled under Honami Kōchū in Kyōhō 4 (1719) — recorded that 69 of those 168 blades had been lost to the Meireki fire. A blade caught in a fire typically suffers a roughened surface and the disappearance of its temper line (hamon), though skilled polishers and smiths could sometimes restore a damaged blade through re-tempering (saiba), a repair technique that matured throughout the Edo period; the sheer scale of the Meireki fire is thought to have sharply increased demand for this restorative craft. A fire that rebuilt the city of Edo itself also created a decisive rupture in the transmission and documented history of the Japanese sword.