Constantinople in the middle Ages was the largest and wealthiest city in Europe, located between the Golden Horn and the Marmara Sea, just at the point where Europe meets Asia.
Exchanges between Europe and India were intensified at this time, but trade was interrupted by the assault on the city of Trebizond by the Turks commanded by sultan Mohammed II since April 7th, to May 29th, 1453 taking over and laying siege to Constantinople, which was renamed Istanbul and became the Ottoman capital, being the end of the Middle Ages and the Byzantine Empire, thereby beginning the Modern Age.
Not only the Arabs occupied Constantinople, but huge territories in the Southeast Europe where their advances reached the gates of Vienna and also in North África, leaving Europe without the Mediterranean Sea trade route they used for obtaining spices, metals, the much needed sugar, this caused the Europeans to seek a new trade route by taking advantage of the inventions that were produced in the beginnings of the Modern Age, facilitating the search for the desired routes to countries of the spices -China and India. These inventions were essential for the discovering enterprises: the compass, which was attributed to the Chinese, which allowed the navigators to be guided through the magnetized guide pointing to the north and the astrolabe, an instrument to measure the height and the position of the celestial bodies, very useful to determine latitude (geographic coordinate systems that define the distance of a point of land to the Equator in angular grades) and longitude (it defines the distance of a point of land to the so called reference meridian, currently Greenwich)before each country used a different one for its maps. The use of the vertical helm placed in the stern and joined to the technical innovations opened new trade routes for the European man, hence the role of paramount importance that it played in 1492 for the discovery and conquest of America.
Taking advantage of these inventions made possible the maritime explorations which were led by Portuguese and the Spaniards.
Thanks to the work of Enrique the Navigator and the fortune inherited from the Templar´s in 1440, the Portuguese had already hired all kinds of scholars, astronomers, cartographers, navigators and sailors from all nationalities in the Segre’s headland Castle, near Cape of Saint Vincent
They began building the best instruments for navigation and made the most accurate and detailed maps that time. The shipyard at the Port of Lagos produced new experimental vessels such as the caravel, which was copied by all the European countries and kingdoms to dominate almost all the rest of the world. Fifty years later, Columbus used her when crossing the Atlantic in 19424
The Portuguese were the pioneers of the ocean navigation by discovering and colonizing the Madeira and Azores islands. The had also explored the coast of África to Gulf of Guinea reaching Cape of Storms later called Cape of Good Hope.
Discovery of America
Christopher Columbus was born in Genoa in the year 1446. Accompanied by his father Domenico Salvago (formerly Scotto) and his mother Mariola Salvago, he arrived in Lisbon with only five years old, being then called Pietro Salvago. In 1453, at just seven years, Pietro was sent to study in Genoa in the convent of the Dominican Fathers of Santa María di Castello, learning to read and write, from there he went to continue studying in Pavia where he learned Latin, astrology and geometry. When his mother died, Pietro had already reached the age of thirteen, he returned to the convent of Genoa with the Dominican Fathers. He continued his studies- geography, cosmography and astrology - and ended his staying in the convent in 1461.
Pietro will soon afterwards become Cristóforo Colombo, a nickname he took at the age of 14 when he set sail acting firstly as a pirate with Vincenzo Colombo (who ended up on the scaffold in 1492), and later he served as privateer in the service of Rene d’Anjou, Count of Provence.
In 1463 he already had the simple name of Colombo and acted as a privateer under the command of Catalan Pere Ramon Sacosta, a sworn enemy of King Juan II, father of Fernando the Catholic.
In the late 1470 Colombo got a job as commercial agent of the house of the Genoese merchants Luigi Centurione who acted as promoter and Paolo di Negri as intermediary in the deal, transporting sugar from Madeira and Genoa and all kind of goods including slaves from Guinea in Portuguese vessels on behalf of the Genoese, calling in Lisbon and Cádiz and at various times in Valencia, where he had the opportunity to meet merchants from Valencia and Alicante, as well as Genoese bankers who later settled in Seville.
This participation in the purchase of sugar had given Colombo the opportunity to travel through the islands of the Atlantic between Lisbon, Porto Santo, the Canaries, Azores and Madeira, these three archipelagos were joined by a wind system and trade routes extending towards the western coast of África to the Gulf of Guinea and northwards to England and beyond, creating an Atlantic navigation circle, this way Colombo had followed the course of the Genoese commercial expansion from the Mediterranean to the Atlantic Ocean, by which he knew the “Volta da Mina”, route followed by the Portuguese sailors to return their country from the Gulf of Guinea and thereby the Atlantic trade winds, i.e., winds whose direction remains constant throughout the year blowing to the west. This experience became a captivating world for Colombo
encouraged him to be an explorer, and he imagined himself as a discoverer of large and attractive islands, which the Flemish and Portuguese from the Azores called Antilia, these mental digressions could actually be related to the later discoveries which he called the Antilles.
The vessels of the Genoese trade convoy following the route to Genoa and Flanders were almost sunk in 1476 in front of the Cape of St. Vincent, in Portugal, when the fleet commanded by the privateer Cristoforo Salvago was attacked by the French privateer Guillaume de Casenove, Vice Admiral of the King of France. The vessel in which Cristóforo Colombo travelled was sunk; he managed to reach by swimming to the town of Lagos, in the Algarve, while Captain Cristóforo Salvago arrived in Seville where he lived for several years.