New routes East: the Conquest
The progress of the Muslims in the Middle East and the invasions of the Barbarians in Europe stopped the flow of spices in the Middle Ages. The Crusaders re-opened the spices route which was soon invested by Venice and Genoa, then Spain and Portugal. This was the time for the European explorers to conquest the East and the Americas. This was the time of Marco Polo, Vasco de Gama, and Christopher Colombus...
The flow of goods from East to West dwindled and by the time the Arabs conquered Alexandria in AD 624 it had virtually stopped all together. The 7th century saw the rise of Islam and and the Arab empire spread from Spain to the border of China. For 400 years very few spices reached Europe, there was very little trade between the Muslim Arabs and the Christian Europe. In the political and commercial chaos of the Dark Ages which resulted from the barbarian invasions, Eurpe had nothing to offer in exchange for goods from Asia.
In the 11th century, the Crusaders played an important role to open again the route to spread the spices in all Europe. In their mission to reach Jerusalem, they crossed countries and cities where spices were already widely used. It opened the door different products, including spices from Cairo and Alexandria in Egypt, Damascus in Syria, Baghdad & Mosul in Iraq and other great cities which were important trading centre because of their strategic location, astride the trade routes to India, Persia and the Mediterranean. The spices were then carried across the Mediterranean to the Italian seaports to the major towns and cities of Europe.
The Rise of Italian Republics...
Venice and Genoa became principal suppliers to the Crusaders and pilgrims to the Holy Land who develop a taste for the foods of that warm climate. The Italian Republics set up trading concessions in the Near East. they grow enormously in prosperity and the bitter rivalery between them lasted until Venice defeated Genoa in 1380 and thereafter controlled trade with the Orient for more than 100 years. In the picture Marco Polo, from a Venitian trader family is entering Khanbaliq (today Beijing) after a long journey through most of Asia with his father and his uncle. In 1269, 24 years after leaving Venice they came back, but Marco Polo was imprisoned and dictated his stories to a cellmate, a book known as "Il Milione" or "The Travels of Marco Polo".
... and the Rise of Portugal.
The story of the Marco Polo journey opened the way to new explorers. In 1418, the Prince Henry of Portugal set up a navigational school and sent out expeditions down to the west Coast of Africa hoping to find a route to the East. In May 1498, the Portuguese explorer Vasco de Gama reached Calicut the most important port of the west coast of India. De Gama returned to Portugal with a cargo of spices and jewels (see picture on the top of the page, from Biblioteca Nacional of Portugal). In 1500, Pedro Alvares Cabral, an other Portuguese explorer discovered Brazil on the way to India and a year later returned with a cargo of papper and other spices. The Venetian monoploy was broken. In 1506, the king Manuel I, made the Lisbon spice trade a crown monopoly. By 1510, after battles with the Arabs who controlled trade in the Indian Ocean, the Portuguese were established at Goa and in Ceylon (Sri Lanka).