Iberian ship development, 1400–1600
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. 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. 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. 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. 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.