On 3/8/1421, the largest fleet the world had ever seen set sail from China. Its mission was "to proceed all the way to the ends of the earth to collect tribute from the barbarians beyond the seas" & unite the whole world in Confucian harmony. When it returned in 10/1423, the emperor had fallen, leaving China in political & economic chaos. The great ships were left to rot at their moorings. Most records of their journeys were destroyed. Lost in China's long, self-imposed isolation that followed was the knowledge that Chinese ships had reached America 70 years before Columbus & had circumnavigated the globe a century before Magellan. Also concealed was how the Chinese colonized America before the Europeans & transplanted in America & other countries the principal economic crops that have fed & clothed the world.Unveiling incontrovertible evidence of these astonishing voyages, "1421" rewrites our understanding of history. Our knowledge of world exploration as it's been commonly accepted for centuries must now be reconceived due to this landmark work of historical investigation.