World’s oldest-known coin mint identified in China

The findings indicate the mint began operating between c. 640 and 550 BC.

Archaeological research at the ancient site of Guanzhuang in the Central Plains of China has revealed evidence of the world’s oldest coin mint, and the earliest-known examples of metal currency ever discovered in China.

The research, which has been published in Antiquity, has offered exciting new insights into the origins of money.

An aerial view of the bronze foundry excavated at Guanzhuang, China. Photo: Dr Hao Zhao.

Between 2015 and 2019, excavations took place at the Eastern Zhou period (c. 770-220 BC) Guanzhuang site, located near the Yellow River in Henan Province. Inhabited between c. 800 and 450 BC, it was an administrative centre and regional power prior to the rise of Imperial China.

Excavations revealed a zone of craft workshops involved in the production of ceramic, jade, and bone artefacts. Part of a bronze foundry was also uncovered, along with the remains of broken and unfinished bronze objects, dozens of used and unused clay coin moulds, and two fragments of copper ‘spade’ coins.

Spade coins are the earliest-known Chinese metal currency, which circulated in the region until being abolished in 221 BC.

Coin SP-1 (pictured) was found in such an excellent state of preservation that its complete shape could be reconstructed. Restored, it has a full-length of a 143mm, a thickness of 0.9mm, and an original weight of no less than 31g. It bears no inscriptions of its face value or where it was cast – as is typical of the earliest spade coins. Of the second spade coin discovered (Coin SP-2), only the handle and clay core survive. Image: Dr Hao Zhao.

Systematic AMS radiocarbon-dating analysis was carried out on material deposits recovered from the excavation pits where the coins were discovered. Their findings indicate the mint began operating between c. 640 and 550 BC, making it the oldest-known, securely dated minting site.

Analysis of the excavated material assemblages suggests that Guanzhuang was a highly organised site that mass produced standardised spade coins.

‘The Guanzhuang foundry started around 770 BC, but at first it mainly produced ritual vessels, weapons, and tools,’ said Dr Hao Zhao from Zhengzhou University and the study’s lead author. ‘It is about 150 years later that the minting activities appeared in this foundry.’

‘Making coins was one of the most revolutionary financial innovations in human history,’ Dr Zhao added.

The development of a standardised metal currency allowed wealth to be easily traded, calculated, and hoarded. In turn, it provided a way of attributing levels of prestige and power.