The New World is one of the names used for the Western Hemisphere, specifically the Americas and sometimes Oceania (Australasia). The term originated in the early 16th century, shortly after America was discovered by European explorers, expanding the geographical horizon of the people of the European middle Ages, who had thought of the world as consisting of Europe, Asia, and Africa only: collectively now referred to as the Old World. The Americas were also referred to as the "fourth part of the world". Americus and Columbus are given a powerful recorded history having connected the New World of the Americas Continent with European explorers.