A Chinese map collector has found a copy of an ancient map he claims proves controversial theories that a famed Chinese mariner was the first to sail to the Americas and circumnavigate the world.Liu Gang says the map supports recent theories that Chinese people sailed to America before Christopher Columbus and charted parts of the world such as Antartica and northern Canada long before Western explorers.
"The map shows us that Chinese discovered the world 70 years before Columbus," Liu said in a public unveiling of the chart. "The map tells us that [mariner] Zheng He discovered the world."
The map is dated to 1763 but is also clearly marked that it is a copy of a map made in 1418. That date coincides with Zheng He's voyages, from 1405 to 1432.
Liu bought the map for about US$500 (A$666) from a map collector in Shanghai in 2001, but only realised its importance after he read Gavin Menzies' best-selling book 1421: The Year China Discovered The World.
In the book Menzies theorises that previously undiscovered world maps drawn up by Zheng He's admirals were copied by European map makers and were extensively used during the voyages of great Western explorers, including Columbus, Ferdinand Magellan, Vasco Da Gama and James Cook.
Much of Menzies' theories are supported by his knowledge of ocean currents, continental trade winds and star navigation that he learned during his life as a British naval commander.
Despite its prominence on best-seller lists, many historians have criticised Menzies' theories for the lack of accompanying evidence.
China's Ming Dynasty banned ocean-going exploration and trade on pain of death after Zheng He's final voyage, largely due to the death of Emperor Zhu Di, who sponsored the voyages.
The huge costs of Zheng's fleets, which often numbered hundreds of ships, were another factor.
The Chinese records of Zheng He's voyages have largely been lost, either purposely destroyed as part of the ban on ocean-going navigation or due to a fire that ravaged Beijing's imperial palace in the 1420s.
Liu believes a lot of the records still exist, but Chinese scholars have largely ignored them.
"I sincerely believe that other maps exist and books exist [that contain evidence of Zheng He's world travels] but no-one has been paying attention to them," Liu says. "It is my purpose to try to wake these [scholars] up."