Between 1492 and 1504, the Italian explorer and navigator Christopher Columbus led four transatlantic maritime expeditions to the Americas in the name of the Catholic Monarchs of Spain. These voyages led to Europeans learning about the New World and were an early breakthrough in the period known in Europe as the Age of Exploration, which saw the colonization of the Americas, a related biological exchange, and the beginning of trans-Atlantic trade. These events, the effects and consequences of which persist to the present, are often cited as the beginning of the modern era.
Born in the Republic of Genoa, Columbus was a navigator who sailed in search of a westward route to India, China, Japan and the Spice Islands thought to be the East Asian source of spices and other precious oriental goods that were otherwise obtainable only through arduous overland routes. Columbus was partly inspired by the 13th-century Italian explorer Marco Polo in his ambition to explore Asia. His initial belief that he had reached "the Indies" has resulted in the name "West Indies" being attached to the Bahamas and the other islands of the Caribbean.
At the time of Columbus's voyages, the Americas were inhabited by Indigenous Americans, and Columbus later participated in the beginning of the Spanish conquest of the Americas. Columbus died in 1506, and the next year, the New World was named "America" after the Italian explorer Amerigo Vespucci, who realized that it was a unique landmass. The search for a westward route to Asia was completed in 1521, when the Magellan expedition sailed across the Pacific Ocean and reached Southeast Asia, before returning to Europe and completing the first circumnavigation of the world.
Background
Many Europeans of Columbus's day assumed that a single, uninterrupted ocean surrounded Europe, Asia and Africa, although Norse explorers had colonized areas of North America beginning with Greenland c. 986. The Norse maintained a presence in North America for hundreds of years, but contacts between their North American settlements and Europe had all but ceased by the early 15th century.
Until the mid-15th century, Europe enjoyed a safe land passage to China and India—sources of valued goods such as silk, spices, and opiates—under the hegemony of the Mongol Empire (the Pax Mongolica, or "Mongol Peace"). With the Fall of Constantinople to the Turkish Ottoman Empire in 1453, European countries sought to compete with the Silk Road dominated by the gunpowder empires through expanded use of ocean voyages to scope out and establish new trade routes.
Portugal was the main European power interested in pursuing trade routes overseas, with the neighboring kingdom of Castile — one of the predecessor kingdoms of present-day Spain — having been somewhat slower to begin exploring the Atlantic because of the land area it had to reconquer from the Moors during the Reconquista. This remained unchanged until the late 15th century, following the dynastic union by marriage of Queen Isabella I of Castile and King Ferdinand II of Aragon (together known as the Catholic Monarchs of Spain) in 1469, and the completion of the Reconquista in 1492, when the joint rulers conquered the Moorish kingdom of Granada, which had been providing Castile with African goods through tribute. The fledgling Spanish empire decided to fund Columbus's expedition in hopes of finding new trade routes and circumventing the lock Portugal had secured on Africa and the Indian Ocean with the 1481 papal bull Aeterni regis.
Navigation plans
In response to the need for a new route to Asia, by the 1480s, Christopher and his brother Bartholomew had developed a plan to travel to the Indies (then construed as roughly all of southern and eastern Asia) by sailing directly west across what was believed to be the singular "Ocean Sea", the Atlantic Ocean. By about 1481, Florentine cosmographer Paolo dal Pozzo Toscanelli sent Columbus a map depicting such a route, with no intermediary landmass other than the mythical island of Antillia. In 1484 on the island of La Gomera in the Canaries, then undergoing conquest by Castile, Columbus heard from some inhabitants of El Hierro that there was supposed to be a group of islands to the west.
A popular misconception that Columbus had difficulty obtaining support for his plan because Europeans thought the Earth was flat can be traced back to a 17th-century campaign of Protestants against Catholicism. This view was popularized in works such as Washington Irving's 1828 biography of Columbus. Knowledge that the Earth is spherical was actually widespread, having been the general opinion of ancient Greek science and gaining support throughout the Middle Ages (for example, Bede mentions it in The Reckoning of Time). The primitive maritime navigation of Columbus's time relied on regular observations of both the stars and the curvature of the Earth.
Diameter of Earth and travel distance estimates
Eratosthenes (who assumed three variables he had not proved: the distance of the Sun, parallel light rays, and that the Earth was spherical) had measured the diameter of the Earth with good precision in the 2nd century BC, and the means of calculating its diameter using an astrolabe was known to both scholars and navigators. Where Columbus differed from the generally accepted view of his time was in his incorrect assumption of a significantly smaller diameter for the Earth, which led him to believe that Asia could be easily reached by sailing west across the Atlantic. Most scholars accepted Ptolemy's correct assessment that the terrestrial landmass (for Europeans of the time, comprising Eurasia and Africa) occupied 180 degrees of the terrestrial sphere, and dismissed Columbus's claim that the Earth was much smaller and that Asia was only a few thousand nautical miles to the west of Europe.
Columbus believed the incorrect calculations of Marinus of Tyre, which had estimated the breadth of the Afro-Eurasian landmass at 225 degrees, leaving only 135 degrees of water. Moreover, Columbus underestimated Alfraganus's calculation of the length of a degree, reading the Arabic astronomer's writings as if, rather than using the Arabic mile (equivalent to about 1,830 meters), he had used the Italian mile (about 1,480 meters). Alfraganus had calculated the length of a degree to be 56+2⁄3 Arabic miles (66.2 nautical miles). Columbus therefore estimated the size of the Earth to be about 75% of Eratosthenes's calculation, and the distance from the Canary Islands westward to Japan as only 2,400 nautical miles (about 23% of the real figure).
Trade winds
There was a further element of key importance in the voyages of Columbus, the trade winds. He planned to first sail to the Canary Islands before continuing west by utilizing the northeast trade wind. Part of the return to Spain would require travelling against the wind using an arduous sailing technique called beating, during which almost no progress can be made. To effectively make the return voyage, Columbus would need to follow the curving trade winds northeastward to the middle latitudes of the North Atlantic, where he would be able to catch the "westerlies" that blow eastward to the coast of Western Europe.
This navigational technique for travel in the Atlantic appears to have been exploited first by the Portuguese, who referred to it as the volta do mar ("turn of the sea"). Columbus's knowledge of Atlantic wind patterns was, however, imperfect at the time of his first voyage. By sailing directly due west from the Canary Islands during hurricane season, skirting the so-called horse latitudes of the mid-Atlantic, Columbus risked either being becalmed or running into a tropical cyclone, both of which, by chance, he avoided.
Funding campaign
Around 1484, King John II of Portugal submitted Columbus's proposal to his experts, who rejected it on the basis that Columbus's estimation of a travel distance of 2,400 nautical miles was about four times too low (which was accurate).
In 1486, Columbus was granted an audience with the Catholic Monarchs, and he presented his plans to Queen Isabella. She referred these to a committee, which determined that Columbus had grossly underestimated the distance to Asia. Pronouncing the idea impractical, they advised the monarchs not to support the proposed venture. To keep Columbus from taking his ideas elsewhere, and perhaps to keep their options open, the Catholic Monarchs nonetheless gave him an allowance, totaling about 14,000 maravedís for the year, or about the annual salary of a sailor.
In 1488 Columbus again appealed to the court of Portugal, receiving a new invitation for an audience with John II. This again proved unsuccessful, in part because not long afterwards, Bartolomeu Dias returned to Portugal following a successful rounding of the southern tip of Africa. With an eastern sea route now under its control, Portugal was no longer interested in trailblazing a western trade route to Asia crossing unknown seas.
In May 1489, Isabella sent Columbus another 10,000 maravedís, and the same year the Catholic Monarchs furnished him with a letter ordering all cities and towns under their domain to provide him food and lodging at no cost.
As Queen Isabella's forces neared victory for Castile over the Moorish Emirate of Granada, Columbus was summoned to the Spanish court for renewed discussions. He waited at King Ferdinand's camp until January 1492, when the monarchs conquered Granada. A council led by Isabella's confessor, Hernando de Talavera, found Columbus's proposal to reach the Indies implausible. Columbus had left for France when Ferdinand intervened, first sending Talavera and Bishop Diego Deza to appeal to the queen. Isabella was finally convinced by the king's clerk Luis de Santángel, who argued that Columbus would bring his ideas elsewhere, and offered to help arrange the funding. Isabella then sent a royal guard to fetch Columbus, who had travelled several kilometers toward Córdoba.
In the April 1492 "Capitulations of Santa Fe", Columbus was promised he would be given the title "Admiral of the Ocean Sea" and appointed viceroy and governor of any land which was newly claimed and colonized for the Crown; he would also receive ten percent of all the revenues from the new lands in perpetuity if he was successful. He had the right to nominate three people, from whom the sovereigns would choose one, for any office in the new lands. The terms were unusually generous but, as his son later wrote, the monarchs were not confident of his return.
Capitulations and royal orders
Capitulations of Santa Fe
The capitulations were signed on 17 April 1492 in the town of Santa Fe, in the Province of Granada. The Capitulations of Santa Fe were the agreements that Christopher Columbus reached with the Catholic Monarchs in order to carry out the voyage. These granted him the lifelong and hereditary title of "Admiral of the Ocean Sea", the title of "Viceroy and Governor" of any lands he might discover in the name of the Kingdom, the right to receive one-tenth of the riches and merchandise, the authority to deal with disputes arising over wealth, and the right to contribute one-eighth of the expedition in exchange for obtaining one-eighth of the profits earned.
Royal provisions ordering caravels to be placed at Columbus's service
Among the various royal provisions and charters granted to Columbus for the realization of his project, one was addressed to some of the residents of the town of Palos because of a sanction that had been imposed on them by the royal council. The royal provision was read on 23 May 1492, at the doors of the Church of Saint George in Palos de la Frontera, in the presence of Columbus, Friar Juan Pérez, and the local authorities. In that royal order, those residents were instructed to place at Columbus's disposal two caravels fully armed and fitted out.
Royal Provision of the Catholic MonarchsAddressed to certain residents of Palos ordering them to deliver two caravels to Christopher Columbus... You well know that, because of certain deeds done and committed by you in disservice to us, you were sentenced by members of our Council to be obliged to serve us for two months with two armed caravels, at your own cost and expense, whenever and wherever it should be commanded by us, under certain penalties, as is set out more fully in the said judgment that was given against you. And now, because we have ordered Christopher Columbus to go with three caravels as commander of the said three caravels to certain parts of the Ocean Sea on matters that concern our service, and we desire that he take with him the said two caravels with which you are thus bound to serve us...
The residents to whom that provision was addressed replied:
... that they were ready to comply with it in every respect, exactly as Their Highnesses command...
— Back of the Royal Provision.
Another, general royal provision granted to Columbus by the Catholic Monarchs compelled the towns on the Andalusian coasts:
...the cities and towns and places on the coast of the sea of Andalusia, as well as of all our kingdoms and lordships (...) You know that we have ordered Christopher Columbus to go with three caravels to certain parts of the Ocean Sea as our captain (...) therefore we command all of you, and each one of you in your respective places and jurisdictions, that whenever the said Christopher Columbus should have need...