The Odawara Campaign (1590) and Japanese Swords: How the Final Siege of Unification Shaped the Blade Industry

The Final Chapter of National Unification—Historical Significance of the Odawara Campaign

In 1590 (Tensho 18), Toyotomi Hideyoshi forced the surrender of the Gohojo clan, the dominant power of the Kanto region, effectively bringing down the curtain on the Sengoku period that had lasted more than a century. The Odawara Campaign was the largest siege of the Sengoku period, mobilizing over 200,000 troops, and concluded with the castle's surrender after approximately four months of siege (April to July).

In the history of swords, this campaign is regarded as one of the important turning points. The end of massive wartime demand and the transition to a peaceful era fundamentally changed the quality, quantity, and direction of sword production.

The Final Wave of Sword Demand Generated by the Massive Military Mobilization

In the Odawara Campaign, which saw the participation of over 200,000 troops, demand for practical swords, spears, and naginata for actual combat temporarily surged. In particular, demand increased for practical swords called kazuchigatana, mass-produced blades, and records remain of swordsmiths from Mino, Bizen, and Soshu responding to large orders.

On the other hand, Toyotomi daimyo and powerful warlords sought custom-made swords from master craftsmen at this opportunity, which was also an excellent stage for swordsmiths of the shintao period to demonstrate their skills. The honor of "delivering swords to the ruler of the realm" had the effect of dramatically raising a swordsmith's reputation.

Swordsmiths in Hojo Territory and the Transformation of Production Centers

The area around Sagami Province (present-day Kanagawa Prefecture), the base of the Gohojo clan, had accumulated a sword culture continuing from the Kamakura period. Some swordsmiths who inherited the techniques of the Soshu tradition had deep ties to the Hojo clan, and it is said that some were forced to relocate their workshops or cease operations due to changed circumstances after the castle's opening.

After the campaign, Tokugawa Ieyasu, who was given the Kanto region, established Edo Castle as his base and began organizing official court swordsmiths. This would become the foundation for later Edo sword culture. The process by which the migration of swordsmiths to the Kanto region influenced the formation of local production centers during the shintao period is also a point of discussion in sword history research.

The Sword Collection Edict (1588) and Its Connection to the Campaign

Two years before the Odawara Campaign, in 1588 (Tensho 16), Toyotomi Hideyoshi issued the Sword Collection Edict. This law, which confiscated swords from peasants and religious institutions, was part of a social reform to thoroughly separate military and civilian populations.

It is said that some of the large quantities of swords confiscated through the sword collection were melted down and converted to agricultural tools and bells, but the reality varied greatly by region and not all were confiscated. However, the direction of "restricting sword ownership to certain social classes" had the effect of organizing the subsequent sword market around the warrior class.

With the Odawara Campaign, the practical demand of the Sengoku period ended, and the Sword Collection Edict restricted sword ownership among the peasant class—this linkage of two historical events became a major catalyst for fixing swords as "the exclusive possession of the samurai class."

Postwar Settlement and the Fate of Famous Swords

After the campaign, swords held by the Hojo clan were distributed among the daimyo as war spoils. Hideyoshi himself was known to have been fond of fine swords, and records remain of swords being granted as rewards for their service in the campaign.

As the Sengoku daimyo were dissolved, transferred, and removed from power repeatedly, famous swords were dispersed and re-accumulated among various families. This forms a preceding phase of the phenomenon of "famous sword organization by daimyo houses" seen in the early Edo period, making the period after the Odawara Campaign a notable milestone in the history of sword circulation.

The Prelude to the Shintao Period

The Odawara Campaign, positioned just before the concept of "shintao"—that is, the classification that distinguishes swords made after the Keicho era (1596-1615) from kotao—corresponds to the "final period of kotao" in sword history.

Among the swordsmiths mobilized for the campaign, many inherited the techniques of kotao while seeking to meet the demands of the new era, and the swordwork of this transitional period is evaluated by appraisers as "suekouto." As peace approached, swords gradually shifted from "tools of war" to aspects of "symbols of samurai prestige" and "works of art"—this major transformation began with the completion of national unification in 1590.

Perspectives on Appreciating and Collecting Suekouto

Suekouto, corresponding to the period around the Odawara Campaign, forms a relatively accessible stratum in the modern sword market. From an appreciation and collection perspective, the first point to understand is that even among suekouto, there is great variation in quality between "mass-produced" and "custom-commissioned" blades.

By comparing the finish of the nakago, the way the signature is cut, and the density of the jigane, the differences can be read to some extent even from photographs.

Furthermore, because swords from the late Sengoku period have passed through both actual combat and long transmission histories, when selecting a sword from this era, the following points should be kept in mind as basic considerations.

• Confirm whether or not the blade has been polished-shortened (nakago reduction to change length)
• Confirm the integrity of the edge and jigane
• Carefully cross-reference the appraisal certificate's description with the condition shown in the photographs
• Clarify any unclear points with the seller before purchase

Viewing Swords in Historical Context

When viewing a single blade with knowledge of a pivotal period such as the Odawara Campaign, the circumstances of the era behind the form and signature come into three-dimensional view. For example, if a blade bears a dated signature from around the Tensho or Bunroku eras, you can tell it was forged during the latest demand of the Sengoku period. With a polished-shortened kotao, you can imagine a history that has passed through two eras: the practical use of Sengoku and the formality of Edo.

When reading product page descriptions and appraisal certificate entries, developing the habit of understanding the manufacturing date in conjunction with historical events of that era transforms the act of selecting swords itself into an exercise in understanding history.