1421 - The Year China Discovered America, investigates a theory that could turn the conventional view of world history on its head: the startling possibility that a daring Chinese admiral, commanding the largest wooden armada ever built, reached America 71 years before Columbus. The documentary examines the mystery surrounding China's legendary Zheng He and the spectacular Ming fleet of treasure junks he commanded in the early 15th century. The special provides a history of the known journeys of Zheng He's fleet and an account of new information uncovered by Gavin Menzies, a former British submarine commander who has spent nine years trying to prove that Zheng He reached America decades before Columbus. Menzies, author of the best-selling book 1421: The Year China Discovered the World, has assembled evidence that he believes substantiates his theory.