Admiral Zheng He is extremely well known in China, where he is considered one of the pioneers of marine exploration.
But he is virtually unknown in the West, where it is widely considered that Columbus discovered the "New World" first in 1492, although many Scandinavian historians claim the Vikings beat him by nearly 500 years.
Gavin Menzies, a retired British submarine commander who is bringing out a book on Zhang He next month, says many academics not just in China but also on the West Coast of the US believe he found North America and Australia during a two-year odyssey which began in 1421.
Mr Menzies told BBC News Online: "It's virtually impossible to still argue that Columbus discovered America, that Cook found Australia or that Magellan was the first to circumnavigate the world. You have to be a crank nowadays to believe that."
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It's virtually impossible to still argue that Columbus discovered America, that Cook found Australia or that Magellan was the first to circumnavigate the world. You have to be a crank nowadays to believe that
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Gavin Menzies
Author
Mr Menzies, whose book 1421: The Year China Discovered The World comes out next month, has spent several years investigating the credibility of the claims about Zheng He, a Muslim eunuch employed by successive Ming emperors.
In 1421, Zheng He's fleet of four mighty junks set sail from Nanjing, a port on the Yangtze river and the then capital of the Chinese Empire.
Each ship was three times the size of Nelson's flagship at Trafalgar, HMS Victory and their triple hulls were more advanced than many 19th century warships.
Mr Menzies said so much teak was needed for their construction that the forests of Vietnam had to be raided, leading to a war with the ancient kingdom of Annam.
Mr Menzies said that although Zheng He himself turned back when they got to Sumatra, he could still lay credit to the exploits of his admirals who he had trained and whose ships he had designed.
Zheng He's fleet gradually split up but Mr Menzies said there was incontrovertible evidence that three of the four ships went to Arabia, the Cape of Good Hope, the Caribbean, South America, the South Pacific, Australia and then the west coast of North America.
He said: "The Chinese set up settlements all along the west coast of North America, from Vancouver Island to New Mexico and inter-married happily with the local Indians.
"When the first Spanish colonialists arrived in the 16th century they found many Chinese, as well as wrecked junks.
"But the diseases the European colonists brought with them wiped out 90% of the Indians, and destroyed the Chinese influence."
Ironically, after the admirals of Zheng He's fleet returned from their global travels they found they were not lauded but castigated.
The Ming dynasty, beset with keeping at bay the Mongol hordes, turned to Confucianism and began a policy of isolationism which lasted 600 years.
Mr Menzies said: "The emperor who commissioned Zheng He's fleet lost control in 1424 and was replaced by his son who slammed the door to the world shut.
"The great ships were mothballed, the admirals were pensioned off, the records were burned and the blueprints for the mighty junks were destroyed."
Now, nearly 600 years on, China is once again trying to restore its place as a global superpower and Zheng He is now seen as a pioneer.
The government of Jiangsu province - home of the former Ming capital Nanjing, which still houses the dry docks where Zheng He's ships were built - is trying to find the funding for an ambitious project.
"They want to rebuild one of his ships, and also to create a museum at Nanjing and to recreate the harbour at Taicang at which he stocked up before the journey. But it will cost millions," said Mr Menzies.
1421: The Year China Discovered the World, is published in the UK on 4 November.