Christopher Columbus. He was an italian navigator and explorer, who traveled across the Atlantic Ocean under the order and support of the Catholica Monarchs from Spain. He left Spain with 3 ships (the Niña, the Pinta and the Santa María) in August, 1492 and arrived in the Americas on October, 12th (thus, the Columbus Day celebration). As a consequence of his expeditions, the concept of the awareness of the new world came up, as it was the opening door of a period of exploration, colonization and conquest.
