The Silk Road was the most enduring trade route in human history, being used for about 1,500 years. Its name is taken from the prized Chinese textile that flowed from Asia to the Middle East and Europe, although many other commodities were traded along the route. The Silk Road consisted of a succession of trails followed by caravans through Central Asia, about 6,400 km in length. Travel was favored by the presence of steppes, although several arid zones had to be bypassed such as the Gobi and Takla Makan deserts. Economies of scale, harsh conditions and security considerations required the organization of trade into caravans slowly trekking from one stage (town and/or oasis) to the other.
Although it is suspected that significant trade occurred for about 1,000 years beforehand, the Silk Road opened around 139 B.C. once China was unified under the Han dynasty. It started at Changan (Xian) and ended at Antioch or Constantinople (Istanbul), passing by commercial cities such as Samarkand and Kashgar. It was very rare that caravans traveled for the whole distance since the trade system functioned as a chain. Merchants with their caravans were shipping goods back and forth from one trade center to the other. In addition to silk, major commodities traded included gold, jade, tea and spices. Since the transport capacity was limited, over long distance and often unsafe, luxury goods were the only commodities that could be traded. The Silk Road also served as a vector for the diffusion of ideas and religions (initially Buddhism and then Islam), enabling civilizations from Europe, the Middle East and Asia to interact.
The initial use of the sea route linking the Mediterranean basin and India took place during the Roman Era. Between the 1st and 6th centuries, ships were sailing between the Red Sea and India, aided by summer monsoon winds. Goods were transshipped at the town of Berenike along the Red Sea and moved by camels inland to the Nile. From that point, river boats moved the goods to Alexandria, from which trade could be undertaken with the Roman Empire. These trade routes have also been instrumental in the spread of diseases and the first pandemics. For instance, the Justinian Plague of 541 (a form of bubonic plague) is believed to have spread to the Mediterranean from its East Asian origins through trade routes.
From the 9th century, maritime routes controlled by the Arab traders emerged and gradually undermined the importance of the Silk Road. Since ships were much less constraining than caravans in terms of capacity, larger quantities of goods could be traded. The main maritime route started at Canton (Guangzhou), passed through Southeast Asia, the Indian Ocean, the Red Sea and then reached Alexandria. A significant feeder went to the Spice Islands (Maluku Islands) in today’s Indonesia. The diffusion of Islam was also favored through trade as many rules of ethics and commerce are embedded in the religion.
The Silk Road reached its peak during the Mongolian Empire (13th century) when China and Central Asia were controlled by Mongol Khans, which were strong proponent of trade even if they were ruthless conquerors. At the same time relationships between Europe and China were renewed, notably after the voyages of Marco Polo (1271-1292).
During the Middle Ages, the Venetians and Genoese controlled the bulk of the Mediterranean trade which connected to the major trading centers of Constantinople, Antioch and Alexandria. As European powers developed their maritime technologies from the 15th century, they successfully overthrew the Arab control of this lucrative trade route to replace it by their own. Ships being able to transport commodities faster and cheaper marked the downfall of the Silk Road by the 16th century.