Gilt-Bronze Horse Trappings from Saitobaru Kofun: A National Treasure of Ancient Japan

Among the most extraordinary archaeological treasures ever unearthed in Japan, the gilt-bronze horse trappings from the Saitobaru Kofun cluster stand as a stunning testament to the craftsmanship and international connections of the ancient Kofun period. Designated as a National Treasure in 1956, this remarkable set of ornamental horse equipment dates to the 6th century and offers a rare glimpse into the political and cultural exchanges that linked the Japanese archipelago with the Korean Peninsula and broader East Asia.

Though officially registered as having been excavated from the Saitobaru Kofun cluster in what is now Saito City, Miyazaki Prefecture, scholarly research suggests these artifacts more likely originated from the nearby Hyakutsukabaru Kofun group. Today, the originals are carefully preserved and periodically exhibited at the Gotoh Museum in the quiet residential neighborhood of Kaminoge, Setagaya, Tokyo — while faithful replicas can be viewed at the Miyazaki Prefectural Saitobaru Archaeological Museum at the very site where they were discovered.

What Are Gilt-Bronze Horse Trappings?

In the Kofun period (roughly 3rd to 7th century), horse trappings were far more than functional equipment. They were symbols of supreme authority and prestige, reserved for the most powerful chieftains and their connections to the Yamato court. A complete set adorned ceremonial horses used in rituals and processions, transforming an ordinary mount into a dazzling display of wealth and political power.

The Saitobaru horse trappings comprise a comprehensive set of ornamental fittings. The collection includes a partial gilt-bronze saddle bow fitting, three openwork apricot-leaf pendants (gyōyō), four plain apricot-leaf pendants, one openwork pommel boss (uzu), one plain pommel boss, nine openwork junction fittings (tsuji-kanamono), six plain junction fittings, sixteen openwork scatter ornaments, two openwork bit cheek plates, and one gilt-bronze buckle. Together, they represent nearly a complete set of ceremonial horse equipment — a rarity among Kofun-period finds.

Why Were They Designated a National Treasure?

The horse trappings were first designated as a National Treasure under the pre-war National Treasure Preservation Act on April 30, 1935. Following the establishment of the post-war Cultural Properties Protection Act, they were re-designated as a National Treasure on June 28, 1956 — the highest level of cultural property protection in Japan. They remain the only National Treasure among archaeological artifacts excavated in Miyazaki Prefecture.

Several factors contribute to this exceptional status. The dragon-motif openwork decoration (ryūmon sukashibori) is unified across the entire set, demonstrating extraordinary artistic coherence and technical mastery. The craftsmanship is remarkably refined, believed to represent the work of highly skilled artisans from the Korean Peninsula, most likely from the Silla kingdom. This identification places these trappings among the finest examples of East Asian metalwork from the 6th century and provides concrete evidence of diplomatic and cultural exchange between the ancient province of Hyūga and the Korean kingdoms.

Historical Significance: A Window into East Asian Diplomacy

The presence of such magnificent horse trappings in southern Kyushu raises compelling questions about the political landscape of 6th-century Japan. During this period, the Yamato court maintained complex relationships with the kingdoms of the Korean Peninsula — Silla, Baekje, and Goguryeo — involving trade, military alliances, and cultural exchange.

The fact that trappings of this caliber were interred in a burial mound in Hyūga province suggests that the individual buried there held considerable political and military importance. Scholars theorize that the occupant of the tomb played a significant role as an intermediary between the Yamato court and Korean Peninsula powers, positioned strategically in southern Kyushu along major maritime trade routes.

Comparable gilt-bronze horse trappings with openwork decoration have been found in numerous Silla-period tombs in Korea, reinforcing the connection between the Saitobaru artifacts and the Korean peninsula. The trappings from Hyūga thus serve as tangible evidence of the far-reaching diplomatic networks that connected ancient Japan to the wider East Asian world.

Highlights and What to Look For

When viewing the horse trappings, several elements are particularly worth noting. The openwork dragon motifs on the junction fittings and pommel boss reveal astonishing precision — delicate curves and flowing lines were cut into thin sheets of gilt bronze with remarkable skill. The openwork scatter ornaments are dome-shaped pieces with tiny bells concealed inside, designed to produce a gentle jingling sound as the horse moved, adding an auditory dimension to the visual spectacle.

The apricot-leaf pendants (gyōyō) are perhaps the most elegant pieces, with their characteristic leaf-shaped silhouettes that would have swayed gracefully from the horse's harness. The contrast between the openwork pieces, with their intricate pierced designs, and the plain companion pieces creates a sophisticated visual rhythm that speaks to the artistic sensibility of the original craftsmen.

Though much of the original saddle bow has been lost over the centuries — the surviving fragments are described as "remnants" (zanketsu) — the remaining edge decorations hint at the former grandeur of the complete set.

Where to See the Horse Trappings

Surrounding Attractions

A visit to either museum location offers opportunities to explore rich cultural surroundings.

Near the Gotoh Museum in Tokyo, visitors can enjoy a stroll through the museum's beautiful Japanese garden, which features seasonal flowers including weeping cherry blossoms in spring and azaleas in early summer. The nearby neighborhood of Futako-Tamagawa offers excellent shopping and dining along the Tama River.

In Saito City, the Saitobaru Kofun cluster itself is a magnificent open-air museum. Highlights include the Oni no Iwaya Kofun — the only tomb in the cluster featuring a stone burial chamber, surrounded by a mysterious earthwork — and the massive Osahozuka and Mesahozuka kofun, the largest burial mounds of their types in Japan and Kyushu respectively. The Kiki no Michi walking path connects numerous historic sites and offers a peaceful journey through landscapes steeped in mythology. Each November, the Saitobaru Kofun Festival features a spectacular torchlight procession with hundreds of participants marching through the ancient grounds.