An expedition of archaeologists has unearthed a 600-year-old Chinese coin on the island of Manda, off the northern coast of Kenya.

“This finding is significant. We know Africa has always been connected to the rest of the world, but this coin opens a discussion about the relationship between China and Indian Ocean nations,” said Dr Chapurukha Kusimba of the Field Museum, who co-led the expedition with Dr Sloan Williams of the University of Illinois at Chicago.

The coin is a small disk of copper and silver with a square hole in the center. It is called ‘Yongle Tongbao,’ and was issued by Emperor Yongle who reigned from AD 1403 to 1425 during the Ming Dynasty. The emperor’s name is written on the coin, making it easy to date.

Emperor Yongle, who started construction of China’s Forbidden City, was interested in political and trade missions to the lands that ring the Indian Ocean and sent Admiral Zheng He, also known as Cheng Ho, to explore those shores.

“Zheng He was, in many ways, the Christopher Columbus of China. It’s wonderful to have a coin that may ultimately prove he came to Kenya,” Dr Kusimba said.

That relationship stopped soon after Emperor Yongle’s death when later Chinese rulers banned foreign expeditions, allowing European explorers to dominate the Age of Discovery and expand their countries’ empires.

The island of Manda was home to an advanced civilization from about AD 200 to 1430, when it was abandoned and never inhabited again. Trade played an important role in the development of Manda, and this coin may show trade’s importance on the island dating back to much earlier than previously thought.

“We hope this and future expeditions to Manda will play a crucial role in showing how market-based exchange and urban-centered political economies arise and how they can be studied through biological, linguistic, and historical methodologies,” Dr Kusimba concluded.