Topic: 1421: The Year China Discovered the World
This is a fascinating book by Gavin Menzies that poses a complete rewrite of history.
"...On the 8th of March, 1421, the largest fleet the world had ever seen sailed from its base in China. The ships, huge junks nearly five hundred feet long and built from the finest teak, were under the command of Emperor Zhu Di's loyal eunuch admirals. Their mission was 'to proceed all the way to the end of the earth to collect tribute from the barbarians beyond the seas' and unite the whole world in Confucian harmony. The journey would last over two years and circle the globe.
When they returned Zhu Di lost control and China was beginning its long, self-imposed isolation from the world it had so recently embraced. The great ships rotted at their moorings and the records of their journeys were destroyed. Lost was the knowledge that Chinese ships had reached America seventy years before Columbus and circumnavigated the globe a century before Magellan. They had also discovered Antarctica, reached Australia three hundred and fifty years before Cook and solved the problem of longitude three hundred years before the Europeans..."
The website provides further information and updated evidence to support the hypothesis.