Europeans in the 16th century divided the world into four continents: Africa, America, Asia and Europe. Each of the four continents was seen to represent its quadrant of the world—Europe in the north, Asia in the east, Africa in the south, and America in the west. This division fit the Renaissance sensibilities of the time, which also divided the world into four seasons, four classical elements, four cardinal directions, four classical virtues, etc.
The four parts of the world or the four corners of the world refers to the Americas (the "west"), Europe (the "north"), Asia (the "east"), and Africa (the "south").
Before the discovery of the New World a commonplace of classical and medieval geography had been the "three parts" in which, from Mediterranean and European perspectives, the world was divided: Europe, Asia and Africa. As Laurent de Premierfait, the pre-eminent French translator of Latin literature in the early fifteenth century, informed his readers:
Asia is one of the three parts of the world, which the authors divide in Asia, Africa and Europe. Asia extends towards the Orient as far as the rising sun ("devers le souleil levant"), towards the south ("midi") it ends at the great sea, towards the occident it ends at our sea, and towards the north ("septentrion") it ends in the Maeotian marshes and the river named Thanaus.
For Laurent's French readers, Asia ended at "our sea", the Mediterranean; Europeans were only dimly aware of the Ural Mountains, which divide Europe from Asia in the eyes of the modern geographer, and which represent the geological suture between two fragmentary continents, or cratons. Instead, the division between these continents in the European-centered picture was the Hellespont, which neatly separated Europe from Asia. From the European perspective, into the Age of Discovery, Asia began beyond the Hellespont with Asia Minor, where the Roman province of Asia had lain, and stretched away to unimaginably exotic and distant places— "the Orient".