Ferdinand Magellan discovered that the world is round and not flat through his historic voyage from 1519 to 1522, where he led the first expedition to circumnavigate the globe with 270 men and 5 ships. Starting in Spain, the expedition traveled south along South America, through the treacherous Strait of Magellan, and then across the Pacific Ocean, becoming the first Europeans to reach Guam, the Philippines, and back to Spain, proving that one can sail around the entire world.