* Image is for illustrative purposes only.Daiei Era
大永（だいえい）
Daiei is the era name that followed Eishō and preceded Kyōroku, and it corresponds to 1521–1528. During this period, the throne passed from Emperor Go-Kashiwabara to Emperor Go-Nara, and the Muromachi shogunate passed from Ashikaga Yoshitane to Ashikaga Yoshiharu. A blade signed "Bizen no Kuni ju Osafune Yosozaemon-no-jō Sukesada saku" with a dated inscription of an auspicious day in the 2nd month of Daiei 3 (1523) survives, showing that the mass-production system of Bizen Osafune continued during the sue-koto period.
Description
Daiei as an Era Name
Daiei is the era name that followed Eishō and preceded Kyōroku. It lasted from the 23rd day of the 8th month of Eishō 18 (Julian calendar September 23, 1521) to the 20th day of the 8th month of Daiei 8 (Julian calendar September 3, 1528). During this period, the throne passed from Emperor Go-Kashiwabara to Emperor Go-Nara, and the Muromachi shogunate passed from Ashikaga Yoshitane to Ashikaga Yoshiharu. It was an era change made for reasons of warfare and calamity, and it coincided with a period when the authority of the Muromachi shogunate was still unsettled in the Kinai region.
Dated Inscription of Osafune Sukesada
As a document that directly corroborates the Daiei period in the history of swords, there survives a blade signed "Bizen no Kuni ju Osafune Yosozaemon-no-jō Sukesada saku" with a dated inscription of an auspicious day in the 2nd month of Daiei 3 (1523) (held by the Tokyo National Museum). In Osafune in Bizen Province (present-day Setouchi, Okayama Prefecture), a group of smiths who called themselves Osafune Sukesada in the late Muromachi period left numerous works, built on forging techniques accumulated since the late Heian period. The dated work of Daiei 3 is one example showing that this activity continued during the Daiei era.
Bizen Production System of the Sue-Koto Period
Osafune in Bizen from the late Muromachi period through the Sengoku period was known as one of Japan's largest sword-producing centers. It overwhelmingly surpassed production centers in other provinces in both quantity and quality, producing custom-ordered blades from warlords across the country as well as mass-produced blades (kazu-uchi mono) to meet battlefield demand. The Daiei era is one cross-section of the sue-koto period, in which this Bizen Osafune production system continued alongside the expansion of Sengoku warfare, and the Sukesada dated works serve as concrete evidence of this.
Position in Sword History
Swords of the Daiei era are rarely discussed on their own, but they are significant in providing a primary physical trace in the form of a dated inscription for tracing the continuity of Bizen production in the sue-koto period, which ran from Eishō through Kyōroku to Tenbun. Apart from stylistic discussion of the Bizen tradition itself, a concrete chronological reference point in the form of dated inscriptions provides material for understanding the production history of the sue-koto period.
Origin of the Era Name "Daiei" and Its Historical Background
The change to Daiei was made in Eishō 18 (1521) on the grounds of warfare and calamity. The source of the era name is said to be a passage from a Chinese classic, showing that the court and shogunate still maintained the traditional rites of era change at that time. However, the Kinai region in this period continued to be marked by political strife, including internal conflict within the Hosokawa clan, and the effective control of the Muromachi shogunate was gradually shrinking. Turning to the provinces, sword-producing regions such as Bizen continued to operate on a logic separate from this instability in central politics, and the Daiei 3 Sukesada inscription is precisely a dated work that shows this continuity of production. The succession of era names from Eishō through Daiei, Kyōroku, and Tenbun directly overlaps with the timeline of the mass-production system at Bizen Osafune in the sue-koto period.
Characteristics of This Era
- Daiei (1521–1528) is a late Muromachi-period era located between Eishō and Kyōroku, a period of succession from Emperor Go-Kashiwabara to Go-Nara and from Ashikaga Yoshitane to Yoshiharu.
- A blade bearing the inscription "Bizen no Kuni ju Osafune Yosozaemon-no-jō Sukesada saku, Daiei 3, 2nd month, auspicious day" survives, substantiating Osafune production activity during the Daiei era.
- Osafune in Bizen from the late Muromachi period through the Sengoku period was one of Japan's largest sword-producing centers, producing both custom-ordered blades and mass-produced blades in large quantities.
- The Daiei era is one cross-section of the sue-koto period, during which this Bizen production system continued alongside the expansion of Sengoku warfare.
- The dated inscription, as primary physical evidence, makes it possible to trace the continuity of sue-koto Bizen production from Eishō through Kyōroku to Tenbun.