Published online by Cambridge University Press: 23 November 2009
Evidence exists which demonstrates that primitive attempts to employ astronomical principles for the purposes of navigation were made by Mediterranean seamen at least a thousand years before the beginning of the Christian Era. But the significant development of nautical astronomy as a science came about at the time when the Atlantic Ocean was being opened up by maritime explorers during the Golden Age of Discoveries, and the lead at the time was taken by the Portuguese under the sponsorship of Prince Henry the Navigator.