/u/jsgunn

I do not know of any sources on Magellan's early life, but it is entirely possible that as a teenager he had copies of Columbus' reports, charts, and other guides to navigation. News of Columbus' discoveries spread fast, especially in Portugal, because weather forced Columbus to stop in Lisbon on the return trip of his first voyage. Among others, Peter Martyr had published a set of tracts based on first-hand account of exploration of the Americas. in the 1511-1530 timeframe.

So in a way, Magellan had access to very good knowledge, even if they may be incomplete. It was known the earth is round, thus Columbus' original plan to sail west to India, even if it was based on incorrect information. As a young man, Magellan joined the 7th Portuguese Carreia da India, which departed Lisbon in 1505 to install Almedia as viceroy in India.

Records are incomplete, but Magellan was mentioned in several engagements and stayed in the Indian ocean area for several years until he returned to Lisbon around mid-1513. There, he seems to have fallen out of favor with the King of Portugal, and in disappointment he went to Seville in 1517 to court the Spanish instead.

His timing was fortuitous, for Charles I of Spain (Charles V HRE Emperor) had launched several expeditions to explore further west from the Americas. Balboa had gone on an overland journey to the west coast of Central America. Magellan and Faleiro were appointed joint commanders of a seaborne expedition that sought to navigate around the southern tip of the Americas. This was a big deal, as only a few decades earlier, Europeans didn't know whether the southern tip of Africa was navigable, either. Not until Dias proved it, anyway.

We know now that Magellan did make it past the so-named Magellan Strait, even if he died in the Philippines and the rest of his expedition completed the circumnavigation without him.