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Massive 2.3-Meter Dakoken Sword Unearthed in Japan: A Remarkable Archaeological Discovery

Japanese archaeologists have unearthed a colossal sword, measuring an impressive 2.3 metres in length, during excavations at the Tomikomaruyama burial mound, approximately 40 kilometres south of Kyoto. 

Dating back more than 1,500 years, this iron sword is believed to have been used to protect the deceased on their journey to the afterlife.

This sword is recognized as the largest intact specimen ever found in Japan, making it an exceptional artifact. Its blade features a slight curvature reminiscent of a snake and represents a typical “dakoken” sword associated with the veneration of the snake deity.

The sword, which has its origins in the Kofun Period, which spanned from 300 to 538 AD. This period witnessed important social, technological and cultural transformations that led to significant changes in the history of Japan.



The Tomikomaruyama burial mound, where this remarkable sword was discovered, dates back to the 4th century AD and marks the early years of the Kofun period. This historic site boasts an impressive diameter of 86 meters and reaches a height of 10 meters.

Over the years, the Tomikomaruyama burial mound has yielded a wealth of priceless artifacts, including agricultural tools, utensils, cylindrical copper vessels, bronze objects, and intricately decorated mirrors adorned with motifs of gods and animals. These finds offer a multifaceted insight into the culture and lifestyle of the period.

In addition to the colossal sword, a bronze mirror with a unique shield shape, 64 cm high and 31 cm wide, was also found in the excavation. The design on the back of the mirror bears a striking resemblance to the motifs seen on “Daryukyo” mirrors from the Kofun period.



Bronze shield-shaped mirror. Credit: Nara Prefectural Archaeological Institute in Kashihara

Kosaku Okabayashi, deputy director of the Kashihara Archaeological Institute in Nara Prefecture, said the discoveries demonstrate the remarkable technological advances of the Kofun period, surpassing previous conceptions and revealing exquisite metal masterpieces from this historical period.

In a layer of clay covering a wooden coffin measuring an impressive 5 metres in length, the team of archaeologists discovered an iron sword and a bronze mirror. Surprisingly, there is no evidence of the grave being robbed, suggesting that the contents of the coffin could have remained intact.

Although the wooden coffin remains unopened, researchers intend to analyse its contents at a later stage. Seigo Wada, director of the Hyogo Prefectural Museum of Archaeology, expressed keen interest in the social position and identity of the individual buried with these extraordinary artefacts. The presence of such an unusual sword and mirror raises expectations for further exploration and study of the coffin’s contents.