Christopher Columbus (c. 31 October 1451 – 20 May 1506) was an explorer, colonizer, and navigator, born in the Republic of Genoa, in what is today northwestern Italy. Under the auspices of the Catholic Monarchs of Spain, he completed four voyages across the Atlantic Ocean that led to general European awareness of the American continents in the Western Hemisphere. Those voyages, and his efforts to establish permanent settlements in the island of Hispaniola, initiated the process of Spanish colonization, which foreshadowed the general European colonization of the “New World“.
In the context of emerging western imperialism and economic competition between European kingdoms seeking wealth through the establishment of trade routes and colonies, Columbus’ far-fetched proposal to reach the East Indies by sailing westward received the support of the Spanish crown, which saw in it a promise, however remote, of gaining the upper hand over rival powers in the contest for the lucrative spice trade with Asia. During his first voyage in 1492, instead of reaching Japan as he had intended, Columbus landed in the Bahamas archipelago, at a locale he named San Salvador. Over the course of three more voyages, Columbus visited the Greater and Lesser Antilles, as well as the Caribbean coast of Colombia, Venezuela and Central America, claiming them for the Spanish Empire.
Never admitting that he had reached a continent previously unknown to Europeans, rather than the East Indies he had set out for, Columbus called the inhabitants of the lands he visited indios (Spanish for “Indians“). Columbus’ strained relationship with the Spanish crown and its appointed colonial administrators in America led to his arrest and dismissal as governor of the settlements in Hispaniola in 1500, and later to protracted litigation over the benefits which Columbus and his heirs claimed were owed to them by the crown.
Washington Irving‘s 1828 biography of Columbus popularized the idea that Columbus had difficulty obtaining support for his plan because many Catholic theologians insisted that the Earth was flat. In fact, most educated Westerners had understood that the Earth was spherical at least since the time of Aristotle, who lived in the 4th century BC and whose works were widely studied and revered in Medieval Europe. The sphericity of the Earth is also accounted for in the work of Ptolemy, on which ancient astronomy was largely based. Christian writers whose works clearly reflect the conviction that the Earth is spherical include Saint Bede the Venerable in his Reckoning of Time, written around AD 723. In Columbus’ time, the techniques of celestial navigation, which use the position of the Sun and the Stars in the sky, together with the understanding that the Earth is a sphere, were widely used by mariners.
Where Columbus did differ from the view accepted by scholars in his day was in his estimate of the westward distance from Europe to Asia. Columbus’ ideas in this regard were based on three factors: his low estimate of the size of the Earth, his high estimate of the size of the Eurasian landmass, and his belief that Japan and other inhabited islands lay far to the east of the coast of China. In all three of these issues Columbus was both wrong and at odds with the scholarly consensus of his day.
As far back as the 3rd century BC, Eratosthenes had correctly computed the circumference of the Earth by using simple geometry and studying the shadows cast by objects at two different locations: Alexandria and Syene (modern-day Aswan). Eratosthenes’s results were confirmed by a comparison of stellar observations at Alexandria and Rhodes, carried out by Posidonius in the 1st century BC. These measurements were widely known among scholars, but confusion about the old-fashioned units of distance in which they were expressed had led, in Columbus’s day, to some debate about the exact size of the Earth.