Juan Senastian Elcano. Amazing story, Magellan didn't set out to cross the globe, only to find a secure way through for his ships to sail to the Spice Islands. It was Elcano who decided to push westwards after Magellan's death and thus completed the first known circuit of this orb.
Magellan died after agreeing to kill a warlord who he personally wanted to convert to Christianity; however he felt duty-bound to follow the request of a powerful overlord on the Philippines, and was killed in the attempt.