Archaeologists in Japan have uncovered a remarkable burial site within the mᴀssive Sakurai Chausuyama Kofun, a keyhole-shaped mound dating to the early Kofun period (250 CE–552 CE), located in Sakurai, Nara Prefecture. The excavation has revealed over 100 ancient bronze mirrors.

Mirror fragments found in the Sakurai Chausuyama mound are shown over an image of a triangular-framed mirror with gods and animals found from another mound at Nara Prefecture. Credit: Kenji Shimizu

The Sakurai Chausuyama Kofun is a monumental 207-meter-long burial mound situated on the left bank of the Hasegawa River in Sakurai City, Nara Prefecture. Designated as a “historic site” by the central government, it has long captured the fascination of archaeologists and historians.

Among the mirrors found are the so-called “Himiko’s mirrors,” featuring a distinctive triangular rim adorned with depictions of gods and animals. Himiko, whose name these mirrors bear, is a semi-legendary figure from early third-century Japan. While absent from Japanese historical records, she is briefly mentioned in Chinese historical texts. Himiko is known for her role as a shaman queen who ruled over the Yamatai-koku kingdom. However, the exact location of Yamatai remains a subject of scholarly debate.

Some of the mirrors uncovered are believed to have been produced from the same mold as Sankakubuchi Shinjukyo mirrors, often referred to as “deity and beast mirrors.” These particular mirrors carry inscriptions dating back to the first year of the Seishi era, corresponding to the year 240 in the calendar of China’s Wei dynasty. Historical texts suggest that Himiko received 100 mirrors as a tribute from the Wei dynasty during that year.

Over the years, excavations at the Sakurai Chausuyama burial mound have yielded a total of 385 fragments of bronze mirrors. In 2010, a study by the Prefectural Archaeological Insтιтute attributed the finds to 81 bronze mirrors, surpᴀssing the previous record of 40 mirrors discovered at the Hirabaru archaeological site in Itoshima, Fukuoka Prefecture.

However, in a recent re-examination of these fragments, researchers have concluded that the excavation has unearthed at least 103 bronze mirrors, setting a new record in Japan.

The mirrors found in this excavation come in 14 different types, including 26 triangular-rimmed mirrors featuring images of gods and animals, 56 China-made mirrors in 10 unique designs, and 21 Japan-made mirrors in three different varieties. Many of these mirrors, especially those from China, are large and intricately decorated, featuring complex patterns and inscriptions.

Shinya Fukunaga, an archaeology expert from Osaka University, emphasized the significance of this discovery. He noted that this find could potentially change the understanding of the political structure of the Yamato State and underscores the central power that existed during that era.

The latest research results are scheduled to be presented at Tokyo’s Yurakucho Asahi Hall on October 8.