The Age of Discovery or the Age of Exploration from the end of the 15th century to the 18th century, was an informal and loosely defined European historical period marking the time period in which extensive overseas exploration emerged as a powerful factor in European culture and the beginning of globalization. It also marks the rise of the period of widespread adoption in Europe of colonialism and mercantilism. Many lands previously unknown to Europeans were discovered during this period, though most were already inhabited. From the perspective of many non-Europeans, the Age of Discovery marked the arrival of settlers and invaders from a previously unknown continent.
Global exploration started with the Portuguese discoveries of the Atlantic archipelagos of Madeira and the Azores, the coast of Africa, and the discovery of the sea route to India in 1498; and, on behalf of the Crown of Castile (Spain), the trans-Atlantic Voyages of Christopher Columbus between 1492 and 1502, and the first circumnavigation of the globe in 1519–1522. These discoveries led to numerous naval expeditions across the Atlantic, Indian and Pacific oceans, and land expeditions in the Americas, Asia, Africa, and Australia that continued into the late 19th century, and ended with the exploration of the polar regions in the 20th century.