The coin, a small disk of copper and silver with a square hole in the center so it could be worn on a belt, is called "Yongle Tongbao" and was issued by Emperor Yongle who reigned from 1403-1425AD 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," said Dr. Kusimba, curator of African Anthropology at The Field Museum. "It's wonderful to have a coin that may ultimately prove he came to Kenya," he added.

Dr. Kusimba continued, "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."

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, off the northern coast of Kenya, was home to an advanced civilization from about 200AD to 1430AD, 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 said.

Note: If no author is given, the source is cited instead.

• Cultures
• Lost Treasures
• Anthropology
• Archaeology

• Bronze Age
• Civilization
• Iron Age
• Mammoth
• Mesopotamia
• Multiregional hypothesis