A team of archaeologists has found a 600-year-old Chinese coin that was buried on the Kenyan island of Manda. Researchers say the find proves China and Africa were trading before European countries began their expansion across the globe.

“This finding is significant,” said Chapurukha Kusimba, co-leader of the expedition and curator of African anthropology at The Field Museum. “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.”

The coin itself is made of copper and silver, and has a square hole in the middle. Researchers say the coin is called a “Yongle Tongbao,” and was issued by Ming Dynasty Emperor Yongle. Emperor Yongle, who reigned from 1403 to 1425 CE, was known to have sent a man named Admiral Zheng He on a mission to explore the Indian Ocean.

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

Researchers say that the island of Manda held an “advanced civilization” from 200 CE to 1430 CE. After that, the island was abandoned and never again inhabited. Chinese expeditions dried up in the wake of Emperor Yongle’s death.

“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,” said Kusimba.

(Image courtesy John Weinstein/The Field Museum)