* Image is for illustrative purposes only.Okadayama Tumulus No. 1 Nukatabe-no-Omi Inscribed Tachi
岡田山1号墳出土 額田部臣銘大刀
Also known as: Silver-Inlaid Round-Pommel Sword of Nukatabe no Omi
Description
Overview
The Nukatabe-no-Omi inscribed tachi is a round-pommel sword excavated from Okadayama Tumulus No. 1 in Matsue, Shimane Prefecture, bearing a silver-inlaid inscription. The text is read as "Nukatabe no Omi" and shows that the Yamato court's be-min system had reached Izumo by the sixth century. It was designated an Important Cultural Property on 6 June 1985 as part of the Izumo Okadayama Kofun artifacts.
The Tumulus and Excavation
Tumulus No. 1 is a late sixth-century keyhole-shaped (zenpo-kohun) mound excavated in 1915 and 1970. The site itself became a National Historic Site on 9 April 1965. The inscription was unknown for years: during conservation at the Gangoji Institute for Research of Cultural Property in 1983, X-ray photography first revealed inlaid characters on the blade.
The Inscription
The recovered text reads "Kakuta-a-omi ... so ... dai-ri ...", with several characters illegible. Its opening is interpreted as Nukatabe no Omi, the name of a local Izumo lord. It is among the older examples of writing on metalwork in Japan and is valued alongside items such as the portrait mirror of Sumida Hachiman Shrine.
Historical Significance
The Nukatabe were one of the be (occupational groups) organized by the Yamato court, and omi was a hereditary title. The inscription suggests that by the sixth century even a region like Izumo had been drawn into the be and uji-kabane systems, with local chieftains incorporated into the central order.
Today
The finds are displayed at the Yakumo-tatsu Fudoki-no-oka Exhibition Hall, and a replica is shown at the Shimane Museum of Ancient Izumo. Its value lies less in the beauty of the blade than in what it tells us about early Japanese writing and state formation.
Legends & Stories
X-rays taken during conservation first revealed the silver-inlaid characters, naming the Izumo chieftain Nukatabe no Omi.