Answer :

Ferdinand Magellan was the first person to circumnavigate, or sail around the entire Earth. This showed the the Earth was round, not flat as previously believed, but also that it was bigger than initially imagined. 

Ferdinand Magellan technically was the first voyager who circumnavigated the globe. Firstly, he visited Spice Islands via the Indian Ocean, and later made his famous voyage that brought him to the Philippines. It turns out that he did cover the entire terrain, but it was not a direct, point A to point A, round-the-world trip. His slave, Enrique, who came to Europe with Magellan returned to his birthplace ten years later. Indeed, Enrique was the first person to circumnavigate the world in one direction, as well.