The Meiwa Great Fire of Edo and Reorganization of Edo Sword Smiths

On February 29, 1772 (the 29th day of the 1st month, Meiwa 9; April 1 in the Gregorian calendar), fire broke out at the priests' quarters of Daien-ji temple on Gyōninzaka slope in the Meguro district of Edo. Driven by powerful southwesterly winds, the fire swept rapidly through the city, reaching as far as Azabu, Shiba, the eastern precincts of Edo Castle, Nihonbashi, Kanda, Shitaya, Asakusa, and Senju before finally being extinguished the following afternoon. Known as the Meiwa Great Fire or the Gyōninzaka Fire, it stands alongside the Meireki Fire of 1657 and the Bunka Fire of 1806 as one of the three greatest conflagrations in Edo's history.

The fire was deliberately set by a wandering monk named Shinshū from Kumagaya in Musashi Province, who was subsequently executed by crucifixion the following year. The scale of destruction was staggering: 169 daimyo residences, over 300 hatamoto estates, 382 temples, and 934 town blocks were burned, with approximately one-third of the city's total area incinerated. Death tolls reached approximately 14,700, with another 4,060 persons listed as missing.

By the Meiwa period (1764–1772), Edo had grown into Japan's largest city with a population of roughly one million. Sword smiths from across the country had concentrated in the capital, drawn by the patronage of the shogunate and domain lords. The Kanda, Asakusa, Shitaya, and Senju districts—all heavily affected by the fire—housed numerous smithing workshops. The losses extended far beyond physical structures: specialized tools (including bellows, grindstones, water tubs, and specialized hammers) were destroyed, as were raw materials and blades in progress commissioned for shogunal and daimyo collections.

The fire coincided with a transitional period in sword history, between the Late Shinto (New Sword) tradition and the emerging Shinshintō (New-New Sword) movement. Water-heart Masahide (Suishinshi Masahide, 1750–1826), who would later publish his influential treatise on swordsmanship and metallurgy and advocate a revival of ancient Yamato and Bizen forging techniques, began his career in the aftermath of this disruption. The reorganization of Edo sword-smithing communities that followed the fire contributed to the generational shift that brought forth the great Shinshintō masters—Ōkei Naotane (1778–1857) and Minamoto Kiyomaro (1813–1854)—who would define sword culture in the late Edo period.

The Meiwa Great Fire thus represents a significant fault-line in Edo sword history, separating an earlier concentrated tradition of Edo smithing from a reorganized landscape that emerged from the ashes of 1772.