Trade has existed for thousands of years. Beginning with simple local exchanges, the distances gradually extend and the first real trade routes appear. One of the earliest known routes is called the Incense Route. From around 1800 BC, navigators begin to travel along the coasts between the Indian subcontinent, where spices such as black pepper and cinnamon are found, and the southern part of the Arabian Peninsula, where a tree that produces incense grows. Dromedary caravans then transport these luxury products across the Arabian desert to Petra, which becomes an important commercial crossroad between Egypt and Mesopotamia. In 331 BC, Alexander the Great, during his conquests, founds the city of Alexandria. Soon, merchant ships link the new city to the rest of the Mediterranean basin. Alexandria then becomes the great warehouse for trade between India and Europe. In East Turkestan, jade is found. This precious stone is much sought after in China, as it is a sign of power and wealth. Nomads then engage in jade trade with the Chinese, notably exchanging it for tea, a drink much appreciated in arid environments. But further north, a confederation of nomadic tribes spreads, and threatens China. In 139 BC, the Chinese emperor sends Zhang Qian as an ambassador to the unknown lands in the West, there to propose an alliance to the Yuezhi against the Xiongnu. But Zhang Qian is captured by the Xiongnu, and is held prisoner for 13 years. On his return to China, he reports to the emperor all he has learned regarding the various peoples of Central Asia and their products. He mentions in particular a majestic race of horses unknown in China. In order to obtain some of these horses, the emperor agrees for the first time to trade silk, which had been forbidden to be exported until then. This is the opening of the Silk Road, which gradually extends to the Middle East. In the west, after the death of Cleopatra, Egypt is absorbed by the Roman Republic, which is in the midst of becoming an empire. Rome is now able to increase its supply of wheat from Egypt, but it covets, above all, goods from the Arabian Peninsula, such as pearls, spices, and especially incense, which is used for offerings and medicine. But there are many intermediaries, and the instability in the region is great. To bypass the Arabian Peninsula, the Romans go up the Nile, and come into contact with the Kingdom of Aksum, where merchants live who have mastered techniques of navigation on the high seas. The romans then open a new route to India, far from the coasts. They import, notably, saffron, perfumes, and diamonds. The new trade route develops rapidly, initiating the decline of the cities of the Arabian Peninsula. Soon after, the Romans come into contact with the Parthians, who import silk from China. The Romans then extend the silk route throughout their empire. In 224, the Parthians fall, and are replaced by the Sassanids, but trade continues. The Roman Empire then moves its capital to Constantinople, which becomes the new commercial crossroads between East and West. From 630 onwards, Muslim conquests threaten the Byzantine and Sassanian empires. By seizing Alexandria, the Arabs cut the road between India and Constantinople. By expanding eastward, they now fight over the territories of Central Asia with China, which wants to make it its protectorate. In 751, the two powers clash in Talas. The battle turns to the advantage of the Arabs, who take Chinese prisoners, who confess to them the secrets of paper and silk manufacturing. After its defeat, China turns away from land routes to concentrate on sea routes, which are safer, and have fewer intermediaries. The country then opens its ports to foreign traders. The Arabs quickly seize this opportunity, and establish themselves at the center of a vast commercial network. The Arabs produce, among other things, carpets, they mine cobalt blue, and they breed horses. In China, they also supply themselves with porcelain. In Southeast Asia and India, in addition to spices, they buy precious stones. In Africa, the trade of gold, slaves, and ivory is growing. Finally, in the north, the Khazars and the Byzantine Empire supply them with European products, such as furs, honey, wood, and slaves. At the heart of this immense network, Arab cities, in full expansion, develop rapidly. In Central Asia, nomadic Turkic tribes threaten the Arab caliphates. Among them, the Seljuk Turks seize Jerusalem in 1076. Christians who go on pilgrimage to the city are quickly persecuted. In reaction, Pope Urban II launches a crusade to Jerusalem. The Italian republics that have mastered navigation see a commercial opportunity. They offer to supply the Christians in the Near East, where they obtain commercial privileges in each of the conquered cities. In 1204, the Republic of Venice diverts the 4th crusade towards Constantinople, which is besieged, and then pillaged. The Byzantine Empire is dismantled, which allows the Italian republics to take over the trade between East and West, all around the Mediterranean basin. In the north of Europe, several trading cities join together to develop a trade route between the Baltic and the North Sea. Novgorod exports furs, Riga produces grain, while Scandinavia exports herring. In the North Sea, textile producers spring up in Flanders and England. In 1453, the Turks seize Constantinople, destabilizing the trade routes between Asia and Europe. Portugal takes advantage of the creation of the caravel, a light ship capable of tackling the oceans, to begin explorations in an attempt to open new maritime trade routes. Along the African coasts, the Portuguese establish trading posts, and take over the slave and gold trades. The objective is now to bypass Africa to reach the Indies. The Spanish monarchy also aims at the Indies, but tries its luck with westward exploration, thus discovering America. Portugal finally reaches the port of Calicut, and discovers a large commercial network. A Mamluk fleet is then charged with chasing away the new competitors. But the Portuguese prevail, and quickly take control of key crossing points, gaining a monopoly on trade in the Indian Ocean. By bringing Asian goods directly to Europe via Africa, and without intermediaries, Portugal becomes rich very quickly, at the expense of the powers that controlled the passage via the Middle East. To avoid competition around the newly discovered territories, Spain and Portugal agree, in 1494, to draw the Tordesillas meridian. The territories to the east can be claimed by Portugal, those to the west by Spain. In America, the Spanish conquistadors discover products unknown in the ancient world, such as tomatoes, tobacco, and potatoes. But in Europe, at first, it’s mainly the discovery of chocolate that interests them. The cocoa trade develops, as well as imports of precious metals and pearls, which are the result of the conquests. But Spain still aims to reach the Indies from the west. Finally, Ferdinand Magellan succeeds in bypassing America, and after his death, his crew reaches the Moluccas, where nutmeg and cloves grow. But the Portuguese are already present in the region, and after conflicts, the two countries establish a new division line. But Spain colonizes the Philippines anyway. In order to develop trade there, the Spaniards have to avoid the Portuguese territories, and they head back to the Pacific. But the sea currents push them back. In 1565, the return route is finally found further north, and makes it possible to link Manila with Acapulco. In America, the Spaniards discover silver mines, which are then intensively exploited using natives as labor. The precious metal is loaded into galleons in Callao, which leave for Acapulco and Manila. In the Philippines, Chinese merchants exchange the silver for spices, tea, silk, and porcelain, which are then brought back to Acapulco. The silver and Chinese products are then transported to Veracruz, from where convoys regularly leave for Seville. While the Iberian Peninsula is rapidly becoming richer, the Dutch, the English, and the French attempt, in turn, to seize trade routes. They found trading posts along the African coast and in the Indian Ocean. They then conquer territories, notably the Caribbean islands, where they develop huge sugar cane plantations, which require a large workforce. In Western Europe, slave traders leave with crockery, weapons, and tools that they exchange in the Gulf of Guinea for slaves. The slaves are then transported under extremely poor conditions to the Americas, and sold to sugar cane and coffee plantations, as well as to mines, such as diamond mines in Brazil. The ships then return to Europe, loaded with sugar, tobacco, rum and precious stones. This trade becomes very profitable, attracting new investors. Over a 200-year period, between 7 and 20 million Africans, depending on estimates, are transported to America. During the 19th century, the abolition of slavery gradually puts an end to this triangular trade. In Great Britain, an industrial revolution begins, thanks largely to the development of the coal-fired steam engine. With the mechanization of the weaving loom, craftsmen become workers, and the textile industry booms. As a result, the demand for cotton jumps. Until then, it came mainly from India. Now, huge plantations are developed in the Caribbean, and in the southern United States. The United Kingdom produces a great deal of textiles at a reasonable price, and is looking for new markets to sell its goods. At the same time, iron and steel techniques are perfected, and the country becomes the largest exporter of iron in the world. Iron and the steam engine revolutionize transportation: the first railroad line links the textile factories of Manchester to the port of Liverpool, where shipments of American and Indian raw cotton arrive. On the seas, steamships gradually begin replacing sailing ships. The United Kingdom strengthens its maritime domination, seizes many territories, and develops a powerful colonial and commercial network. In 1854, France obtains permission from Egypt to build a canal linking the Mediterranean to the Red Sea. Such a canal had already been built in ancient times by the Pharaohs, but had disappeared by the 8th century. In 1869, the Suez Canal is inaugurated, and makes it possible to travel the route to India in 60 days on a steamship, compared to six months with a sailing ship via Africa. However, the European powers do not turn away from the African continent. After expeditions inland, European countries meet in Berlin to divvy up Africa and regulate colonization. The peoples of Africa are subjugated, and their resources plundered. In the south, large reserves of gold and diamonds are discovered. In Central Africa, ivory is exploited. In addition, huge plantations are developed, notably for rubber, necessary for the manufacture of boots and tires for the developing automobile industry. Plantations also appear for coffee, cocoa, tobacco, and other products that are intended for European and American markets. In America, the United States extends its influence. In 1904, they buy, from the French, the abandoned construction site for an inter-oceanic canal. The canal would considerably shorten the maritime route between the Pacific and Atlantic oceans. Ten years later, the Panama Canal is inaugurated, with this new, key passageway controlled by the United States. During World War I, new oil-powered weapons appear on land, at sea, and in the air. At the end of the war, the demand for oil skyrockets, while the automobile and aviation industries develop. At that time, oil comes mainly from the United States, Mexico, and the Caspian Sea. But soon, and especially after World War II, huge deposits are discovered in the Middle East and America. This strategic resource becomes abundant and cheap, and all trade intensifies. The aviation boom makes it possible to trade across the world via the air. This is the beginning of globalization, i.e., the acceleration of trade on a worldwide scale. But the situation in the Middle East and Africa is increasingly unstable. In 1967, the Six-Day War takes place. Israel occupies the Sinai up to the banks of the Suez Canal, which is then closed for 8 years, forcing ships to bypass Africa. In addition, in the 1970s, two oil shocks cause the price of oil to increase dramatically. Countries that depend on this so-called black gold, without producing it, turn to other types of energy, including nuclear power. Uranium becomes a very popular resource. Mainly extracted from mines in Canada and the Congo, new deposits are quickly exploited all over the world. In the 1970s and 1980s, the United States sees a boom in a relatively new and very promising sector: electronics and computer technologies. Apple launches their first personal computer, and it’s an immediate success. Japan quickly follows the USA, beginning a period of dazzling technological development in its automobile and electronics industries. Several countries in the Far East are inspired by Japan, and specialize in the export of electronic components. Rare earths - metals needed in the manufacture of electronics - become a strategic raw material, while the vast majority of the deposits are discovered in China. In 2001, China becomes a member of the World Trade Organization. The country attracts foreign companies thanks to its cheap labor force. At the same time, advantages are granted to foreign investors, and export quotas are abolished. Soon, textiles 'made in China' flood American and European markets. Many companies relocate their factories to China. The country gradually becomes the world's factory, with its economy experiencing explosive growth, allowing for rapid development. To secure its economy, in 2013 the country begins the creation of the new silk roads. The objective is to ensure its supply of raw materials, and also to increase its exports of manufactured products, steel, and aluminum. Throughout the world, roads, railroads, and seaports are massively financed by China, with the aim of connecting the country to all continents. New initiatives are being discussed, such as the construction of a railroad line that would link China to the United States through a tunnel under the Bering Strait, or the construction of an inter-oceanic canal in Nicaragua. While some countries are opposed to this project, China has already convinced about 140 countries to host these new Silk Roads, which should be finalized by 2049, when the People's Republic of China will celebrate its 100th anniversary. According to some estimates, the world's largest trade is in arms, followed by the drug trade, with an estimated annual turnover of nearly 500 billion dollars. This clandestine trade is controlled by criminal networks. Opium poppies are produced in Asia, in the Golden Triangle and the Golden Crescent. Cannabis resin is mainly produced in Morocco, and cocaine comes mainly from Colombia. The drugs are transported by different routes to Europe and the United States, which are the biggest consumers. Today, the main maritime trade route circles the globe, passing through strategic straits and channels. It passes through North America, the Panama Canal, Europe, the Mediterranean, the Suez Canal, the Indian Ocean, and Asia. Moreover, the search for new trade routes never stops. At the North Pole, the melting of the ice caused by climate change makes it possible to envisage the opening of new maritime routes that are shorter, and therefore less costly in terms of fuel, while also avoiding taxes levied when having to pass through the Suez or Panama canals. These new routes could benefit Russia and Canada in particular. The major powers well-understand the stakes at play in these potential future routes. The United States and the European Union are demanding free navigation, while China intends to develop a Polar Silk Road.