The Shosoin's Treasure Swords — Emperor Shomu's Beloved Blades and Tempyo Court Sword Heritage

The treasures preserved at Todai-ji Shōsōin have as their foundation items of treasured affection that Empress Komyo presented to the Great Buddha on the 49th day memorial of Emperor Shomu in Tenpyo Shoho 8 (756). Among these are included valuable swords and blades that convey the courtly sword culture of the Nara period to the present day.

Swords and Blades Recorded in the Registry of National Treasures

The inventory of donated items, the "Todai-ji Kenmotsucho," commonly known as the "Kokka Chinpo Cho (Registry of National Treasures)," records the items and forms of the dedicated swords and blades. From the records contained therein, we can see descriptions such as the following, and it is evident that the court of that time valued continental-style swords and blades as ritual implements.

• Tang swords (karatachi): 13 pieces
• Tang-style swords (karayō no tachi): 6 pieces

Gold, Silver, and Mother-of-Pearl Decorated Tang Sword

Among the Shōsōin swords and blades, the most renowned is the gold, silver, and mother-of-pearl decorated Tang sword (kingin-den kazari no karatachi). It is a ceremonial sword about 99.9 cm in overall length, and the following decorations are applied to it.

• Tsuka (hilt): Wrapped in sharkskin
• Saya (scabbard): Birds, beasts, and arabesque patterns are depicted using the togidashi maki-e technique
• Metal fittings: Openwork is applied, and crystal and glass beads are inlaid

It is believed to have been made as a sword of dignity worn in ceremonial settings, not for actual combat.

The Rediscovery of the Yang Treasure Sword and Yin Treasure Sword

The "Yang Treasure Sword" (yo-hoken) and "Yin Treasure Sword" (in-hoken), said to be heirlooms of Emperor Shomu, were brought out after being presented to the Shōsōin, and their whereabouts were unknown for a long time. In Meiji 40-41 (1907-08), a complete set of altar-stabilizing implements, including 6 large swords, was excavated from near the Rushana Buddha (Great Buddha) mandala platform at Todai-ji. These are designated as the National Treasure "Todai-ji Kondo Chindan-gu," but when X-ray investigation was conducted in 2010, gold inlay inscriptions reading "Yo-ken" and "Yin-ken" were confirmed on 2 of the sword blades. This revealed that they were identical to the Yang Treasure Sword and Yin Treasure Sword, whose whereabouts had been unknown for a long time since being taken from the Shōsōin, and they are known as a dramatic example concerning the transmission of ancient swords and blades.

Why Have They Endured for Over Twelve Hundred Years—Imperial Seal and Azekura Construction

Behind the transmission of the Shōsōin treasures in their Nara-period state to the present day lies a tradition of rigorous management. The treasure repository of the Shōsōin is protected by imperial seal (chokufū), which cannot be opened without the emperor's permission, and opportunities to open it have been strictly limited. The elevated-floor azekura-zukuri construction of the treasure repository and the protection provided by the karabitsu (Chinese-style chests) in which the treasures were stored helped to moderate sudden changes in temperature and humidity, contributing to the preservation of treasures containing many organic materials. Examples of crafted objects combining metal, wood, leather, and thread—such as swords and blades—remaining together as transmitted heirlooms rather than excavated materials are extremely rare worldwide, and the greatest value of the Shōsōin swords lies in conveying the appearance when they were in use as it was.

The Form of Ancient Swords—The World of Straight Swords Without Curvature

The Shōsōin sword group exhibits the style of jokoto (ancient swords) from before Japanese swords had curvature. The blades are fundamentally straight swords, and the cross-sectional construction shows examples such as the kiriha-zukuri where the blade edge is slanted. This is a different structure from the later shinogi-zukuri tachi, and the influence of continental sword styles is evident. The fact that both ceremonial swords emphasizing decoration of the tsuka and saya and practical swords as weapons were presented indicates that swords of that time had two roles: as ritual implements and as weapons.

"Tachi" and "Tachi"—How Notation Tells Sword History

In sword history, there is a convention of distinguishing straight swords of ancient times without curvature as tachi and those with curvature that developed from the Heian period onwards as tachi (both read as "tachi"). The notation "Tang tachi" and "Tang-style tachi" seen in the Registry of National Treasures refers to the former, and it is understood that imported goods from the Tang and domestically produced items following their style were recorded distinctly. From the distinction in the catalog, one can discern that the Nara court was clearly conscious of imported cultural objects and their domestication, making it interesting as a prelude to the subsequent development of the Japanese sword incorporating continental styles and progressing toward its own distinctive form.

The Perspective of Appreciation—Viewing External Fittings and Blade Separately

When appreciating Shōsōin swords and blades, it is helpful to separate the viewing of the external fittings and the blade.

While later Japanese sword appreciation centers on the hamon and the working of the jihada, the basic approach to appreciating ancient swords is to savor them as comprehensive craftsmanship combining blade and external fittings.

Opportunities to View the Shōsōin Treasures

The Shōsōin treasures are not on permanent display; a portion of the treasures selected each year is exhibited at the "Shōsōin Exhibition" held annually in autumn at the Nara National Museum. Some years feature swords, blades, and sword fittings, providing a precious opportunity to observe the details of Tenpyo craftsmanship closely. When viewing the exhibition, if you pay attention not only to the maki-e on the saya and the workmanship of the metal fittings, but also to the silhouette itself of the straight sword without curvature, you should be able to sense the difference from the later tachi.

The Height of Tenpyo Sword Culture

The collection of prized swords at the Shōsōin demonstrates that the Nara court, while absorbing continental culture, was highly refining swords and blades in the aspects of ritual and decoration. Before the establishment of the later curved tachi, they represent the pinnacle of the world of ancient swords based on straight swords.

Those interested in sword culture of the Nara and early Heian periods are invited to view TOUKENZA's columns and sword lists together to see the changes in sword forms across periods.