Due to centuries of constant conflict, warfare and daily life in the Iberian Peninsula were interlinked. Small, lightly equipped armies were maintained at all times. The near-constant state of war resulted in a need for maritime experience, ship technology, power, and organization. This led the Crowns of Aragon, Portugal, and later Castile, to put their efforts into the sea.
Due to geography, Iberian countries had greater access to the sea than did much of Europe; this allowed the Iberian kingdoms to become a people of mariners and traders. These people had the motivation to move; they were close to the wealth of Africa and the Mediterranean. Expansion and development of ship technology were due to commercial, military and religious endeavors.
By 1411, Portugal was no longer fighting Castile. In 1415, it conquered Ceuta, its first overseas colony.Roger C. Smith. Vanguard of the Empire: ships of Exploration in the Age of Columbus. (Oxford University Press, New York: 1993)p. 4 The crusades cemented trade and external alliances. Portugal wanted to protect its coast from Muslim raids and secured their base in the Mediterranean. They were able to attack Muslim commerce while taking part in the trade of gold, slaves, and ivory. As a seafaring people in the south-westernmost region of Europe, the Portuguese became natural leaders of exploration during the Middle Ages. Faced with the options of either accessing other European markets by sea, by exploiting its seafaring prowess, or by land, and facing the task of crossing Castile and Aragon territory, it is not surprising that goods were sent via the sea to England, Flanders, Italy and the Hanseatic league towns.
One important reason was the need for alternatives to the expensive eastern trade routes that followed the Silk Road. Those routes were dominated first by the republics of Venice and Genoa, and then by the Ottoman Empire after the conquest of Constantinople in 1453, which barred European access. For decades the ports in the Spanish Netherlands produced more revenue than the colonies, since all goods brought from Spain, Mediterranean possessions, and the colonies were sold directly there to neighbouring European countries: wheat, olive oil, wine, silver, spice, wool and silk were big businesses.
The gold brought home from Guinea stimulated the commercial energy of the Portuguese, and its European neighbors, especially Spain. Apart from their religious and scientific aspects, these voyages of discovery were highly profitable.
They had benefited from Guinea's connections with neighboring Iberians and north African Muslim states. Due to these connections, mathematicians and experts in naval technology appeared in Portugal. Portuguese and foreign experts made several breakthroughs in the fields of mathematics, cartography and naval technology.
In 1434 the first consignment of African slaves was brought to Lisbon; slave trading was the most profitable branch of Portuguese commerce until India was reached. Throughout the fifteenth century, Portuguese explorers sailed the coast of Africa, establishing trading posts for several tradable commodities, as firearms, spices, silver, gold, slaves.
Portugal were able to have a unique evolution of ships because they were on a geographically crucial land area, one that was literally a hinge between Northern and Southern waters. When there was no reason to expand the development of ships, their development was partially stagnant, even though they were not perfected yet. People would utilize mainly two kinds of ships: longships and roundships (dromonds). Longships were reliant on oarsmen and they tended to be used as warships. Roundships, on the other hand, used sails and tended to be used for carrying freight.John Masefield. On the Spanish Main. (London, Methuen: 1925)p. 229 These ships met the conditions of the sea but not in a perfected sense. The galley (longship) had to be light so that the men could propel it and it had to be long enough so enough men could move the ship. These specifications made it impossible for the ship to be adequately provisioned for a long voyage. As long as the longship was not venturing too far from any given port, she did her job, but clearly for the voyages that would make Spain and Portugal famous, she was simply not cut out for the work. The roundship was able to hold more provisions and she was able to resist more perilous weather than the longship but was impossibly slow, so almost useless as a ship meant to work in warring conditions.John Masefield. On the Spanish Main. (London, Methuen: 1925)p. 229 These ships were important for their intended jobs, but in no way capable of maritime exploration to distant seas. If Iberians wanted to travel further, they had to utilize different technologies to propel the advancement of ships. Iberian peninsular kingdoms were exposed to both Northern and Southern ships from surrounding states. The Mediterranean tended to rely on triangular lateen sails and the use of actual tools to correct navigation. Lateen sails were such an innovation because they had the ability to carry a ship with even the smallest of breezes.Peter Russell. Prince Henry 'the Navigator': A Life. (Yale University Press, United States: 2001)p. 227 Atlantic sailors tended to utilize a stouter, heavier Baltic cog, lapstrake, planked cargo ship with a single square sail that had axial stern rudders that was meant to help in the stormy waters they were accustomed to.Roger C. Smith. Vanguard of the Empire: ships of Exploration in the Age of Columbus. (Oxford University Press, New York: 1993)p. 6
Background The cultural context of the Iberian Peninsula was different from that of the rest of Continental Europe from the Middle Ages, due to contact with Moorish culture and the isolation provided by the Pyrenees. Doctrines, equipment, and tactics differed from those found in the rest of Europe.
The forces were capable of quickly moving long distances, allowing a quick return home after battle. Wars were fought mainly at borders, in no man's land, where skirmishers lived, people who were used to a life of sacking enemy posts and villages. On land, these wars combined some European methods with techniques from Muslim raiders in Al-Andalus. These tactics consisted of small groups who attempted to catch their opponents by surprise, through an ambush. In Mombasa Vasco de Gama resorted to piracy, looting Arab merchant ships, which were generally unarmed trading vessels without heavy cannons.
There were obstacles to work around, such as the dependence on wood for the construction of ships. Geography benefited Portugal by allowing them open access to the water and a suitable coast for ports, but they also had to deal with scarce forests from which to procure trees. In order to encourage shipbuilders, the government would give specific subsidies to certain areas. This was the case in Lisbon, where the government completely eliminated the tax on trees from the royal forest, for trees that would be made into ships that would be over one hundred tons.Roger C. Smith. Vanguard of the Empire: Ships of Exploration in the Age of Columbus. (Oxford University Press, New York: 1993)p. 8 Fewer numbers of trees meant that the people working on the construction would not be allotted room for mistakes, so the ships being newly built were clearly being built with the newest of ship technologies which led to the development of Portuguese expansion through the water.
Spain had an easier time with shipbuilding because it was more forested than Portugal. This is not to say that Spain had a limitless supply of trees, but it did allow them more room for ship variation. Spain did not direct its people to fell trees because of their desire for tree conservation; this was because of the assumed necessity for firewood, and the need for trees to provide acorns and shelter for cattle.David C. Goodman. Power and Penury. (Cambridge University Press, New York: 1988)p. 90 The Spanish monarchy urged people to replace the trees that they cut down by encouraging that for every one felled, two seeds should be planted. What unfortunately tended to occur was the simple transplanting of trees to areas with recently cut down forests. This often resulted in trees that died because they were not able to properly adjust to the new environment.David Goodman. Spanish Naval Power, 1589–1665. (Cambridge University Press: Great Britain: 1997)p. 110 It was not until the 1560s and 1570s that Philip II began to show actual interest in the timber for shipbuilding and began allocating definite numbers of oaks trees that needed to be set in certain districts. There were definite laws that were being enforced with special forest guards that reported directly to the king; this even resulted in some corporations pleading poverty.David C. Goodman. Power and Penury. (Cambridge University Press, New York: 1988)p. 90 The Spanish were excellent shipbuilders; later on in the century, ships themselves were used as items of commerce. The English alone have records of buying six galleons from the Spanish in order to build up their own fleet. Even with a dwindling supply of trees, the profitable avenue of shipbuilding encouraged construction. Shipbuilding became integrated into the Spanish economy; areas specialized. Seville, for example, was known for the repairing of ships, the manufacture of sails and the making of biscuits and casks for shipyard provisions.Roger C. Smith. Vanguard of the Empire: Ships of Exploration in the Age of Columbus. (Oxford University Press, New York: 1993)p. 10 These commercial interests financed the continual development of ships. As long as there was a need for better, faster, stronger ships, people were able to improve technologies, therefore making it more probable for ships to be able to venture further from the shore and eventually across an entire ocean.
Long before Castile, Portugal had colonized the Atlantic islands, Madeira, the Azores, Cape Verde, Sao Tome... it had established a marine route circling Africa, with numerous coastal enclaves along the route.
With the colonization of the Atlantic islands and the African enclaves, Portugal had enough forests to build its fleet and income to finance the construction. For example, Madeira island, literally Wood island, was uninhabited and covered with hardwood virgin forest when it was discovered and colonised.
Besides coastal exploration, Portuguese ships also made trips further out to gather meteorological and oceanographic information. These voyages revealed the archipelagoes of Bissagos Islands where the Portuguese were defeated by native people in 1535,Edward Stallibrass, 'The Bijouga or Bissagos Islands, West Africa', in Proceedings of the Royal Geographical Society and Monthly Record of Geography, Vol. 11, No. 10 (Oct., 1889), p. 595. Trindade and Martim Vaz, Saint Peter and Saint Paul Archipelago, Fernando de Noronha, Corisco, Elobey Grande, Elobey Chico Annobón Island, Ascension Island, Bioko Island, Falkland Islands, Príncipe Island, Saint Helena Island, Tristan da Cunha Island and Sargasso Sea.
The knowledge of wind patterns and currents, the trade winds and the oceanic gyres in the Atlantic, and the determination of latitude led to the discovery of the best ocean route back from Africa: crossing the Central Atlantic to the Azores, using the winds and currents that spin clockwise in the Northern Hemisphere because of atmospheric circulation and the effect of Coriolis, facilitating the way to Lisbon and thus enabling the Portuguese to venture farther from shore, a maneuver that became known as the "volta do mar" (). In 1565, the application of this principle in the Pacific Ocean led the Spanish making the Manila Galleon trade route.