Thoai Ngoc Hau (1761-1829), a famous general, helped Nguyen Anh found the Nguyen dynasty (1802-1945). He and his wives were buried in the southern province of An Giang.

The excavation of their tombs was carried out on September 19 by local experts. They discovered a number of artefacts buried near the tombs of Chau Thi Te and Truong Thi Met, his first and second wives.

The name on the coin was Minh Duc Thong Bao, minted under the reign of Nguyen Nhac (1788-1793). The discovery in the tomb of the high ranking mandarin's wife has been seen as a possible breakthrough by archaeologists.

According to Pham Huu Cong, it could relate to a secret that had never been made public. "Perhaps the couple had a relationship with the Tay Son movement, the Nguyen kings' foes, and kept the coin as a momento, despite the trouble it could cause. When Chau Thi Te died in 1826, the mandarin buried this coin with her," he said.

Cong also noted that many of the objects they had found had been buried outside of the tombs. This could be another way of burying the dead, he added. "Archaeologists should bear this in mind during future excavations, especially Nguyen dynasty graves. We should also look at previous sites to see if there is anything we missed," Cong said.

Archaeologists unearthed 523 objects ranging from pottery to bronzeware, but perhaps the most spectacular find was a hat adorned with 33 gems that probably belonged to a high ranking mandarin.