Trade routes have popped up throughout ancient history, stitching places of production to places of commerce. Scarce commodities that were only available in certain locations, such as salt or spices, were the biggest driver of trade networks, but once established, these roads also facilitated cultural exchanges—including the spread of religion, ideas, knowledge, and sometimes even bacteria.

1. The Silk Road

The Silk Road is the most famous ancient trade route, linking the major ancient civilizations of China and the Roman Empire. Silk was traded from China to the Roman Empire starting in the first century BCE, in exchange for wool, silver, and gold coming from Europe. In addition to fostering trade, the Silk Road also became a vital route for the spread of knowledge, technology, religion, and the arts, with many trading centers along the route, such as Samarkand in modern-day Uzbekistan, also becoming important centers of intellectual exchange.

The Silk Road originated in Xi’an, China, and travelled alongside the Great Wall of China before crossing the Pamir Mountains into Afghanistan and on to the Levant, where goods were loaded on to ships destined for Mediterranean ports. It was rare for tradespeople to travel the full 4000 miles, so most plied their trade on sections of the route. As the Roman Empire crumbled in the fourth century CE, the Silk Road became unsafe and fell out of use until the 13th century, when it was revived under the Mongols. Italian explorer Marco Polo followed the Silk Road during the 13th century, becoming one of the first Europeans to visit China. But the famous route may have spread more than trade and cross-cultural links—some scientists think it was merchants traveling along the route who spread the plague bacteria that caused the Black Death.

2. The Spice Routes

Portugal had a significant presence in Asia and maintained a monopoly on the spice trade. Câmara, Wikimedia Commons // Public Domain

Unlike most of the other trade routes in this list, the Spice Routes were maritime paths linking the East to the West. Pepper, cloves, cinnamon, and nutmeg were all hugely sought-after commodities in Europe, but before the 15th century, North African and Arab middlemen controlled access to trade with the East, making such spices extremely costly and rare. With the dawning of the Age of Exploration (15th to 17th centuries), as new navigation technology made sailing long distances possible, Europeans took to the seas to forge direct trading relationships with Indonesia, China, and Japan. Some have argued it was the spice trade that fueled the development of faster boats, encouraged the discovery of new lands, and fostered new diplomatic relationships between East and West (it was partly with spices in mind that Christopher Columbus set out on his famous voyage in 1492).

The Dutch and English especially profited from the control of the spice trade in modern-day Indonesia, particularly the area known as the Moluccas, or Spice Islands, which was the only source of nutmeg and cloves at that time. Wars were fought, lands colonized, and fortunes made on the back of the spice trade, making this trade route one of the most significant in terms of globalization.

3. The Incense Route

The Incense Route developed to transport frankincense and myrrh, which are only found in the southern end of the Arabian Peninsula (modern Yemen and Oman). Frankincense and myrrh are both derived from tree sap that’s dried in the Sun; these nuggets of sap can then be burned as incense or used as perfume, and were also popular in burial rituals to aid embalming. The camel was domesticated around 1000 BCE and this development allowed the Arabs to begin transporting their valuable incense to the Mediterranean, an important trade hub. Frankincense and myrrh became a significant commodity for the Romans, Greeks, and Egyptians—it was said the Roman emperor Nero had a whole year’s harvest of frankincense burned at the funeral of his beloved mistress.

The trade flourished, and the overland route was, at its height, said to have seen 3000 tons of incense traded along its length every year. Roman historian Pliny the Elder wrote that it took 62 days to complete the route, although it’s clear that at times, the exact route shifted when greedy settlements pushed their luck and demanded taxes that were too high from the caravans coming through. By the first century CE, this ancient overland route was largely redundant, as improved boat design made sea routes more attractive.

4. The Amber Road

Amber has been traded since about 3000 BCE, with archaeological evidence revealing amber beads from the Baltics having reached as far as Egypt. The Romans, who valued the stone for both decorative and medicinal purposes, developed an Amber Road linking the Baltics with the rest of Europe.

Large deposits of amber are found under the Baltic Sea, formed millions of years ago when forests covered the area. The amber washes ashore after storms, and can be harvested from the beaches across the Baltic, which is how many local amber traders built their business. However, during the crusades in the 12th and 13th centuries, the Baltic became an important source of income for the Teutonic Knights, who were granted control of the amber-producing region. The Knights persecuted the local Prussians brutally, and put anyone attempting to harvest or sell amber to death. Today, you can find traces of the old Amber Road in Poland, where one of the major routes is known as the “Amber Highway.”

5. The Tea Horse Road

This ancient route winds precipitously for more than 6000 miles, through the Hengduan Mountains—a major tea-producing area in China—and on to Tibet and India. The road also crosses numerous rivers, making it one of the most dangerous of the ancient trade routes. The main goods traveling the route were Chinese tea and Tibetan warhorses, with direct trades of tea-for-horses and vice versa being the main goal of merchants plying the route. Parts of the route were used starting c.1600 BCE, but people began using the entire path for trade from around the seventh century CE, and large-scale trade began taking place starting in the Song dynasty (960–1279).

At least one piece of research suggests that between 960–1127, some 20,000 Tibetan warhorses were traded along the route every year in exchange for an eye-watering 8000 tons of tea. As sea routes became more popular, the road’s significance lessened. But during World War II, it once again gained importance as the Japanese blocked many seaports, and the Tea Horse Road became a key route for supplies traveling between inland China and India.

6. The Salt Route

Salt has long been a precious commodity—it’s been used to flavor and preserve food, and as an antiseptic, for example. But easily harvested salt was a scarce commodity in antiquity, so areas rich in the mineral became important trading centers. Routes connecting these centers to other settlements also became commonplace. Of the many such routes that sprang up, one of the most famous was the Roman Via Salaria (Salt Route), which ran from Ostia, near Rome, across Italy to the Adriatic coast. Salt was so precious, it made up a portion of a Roman soldier’s pay. It is from this that we get the word salary (from sal, the Latin word for salt) and the phrase “not worth his salt”—the latter because a soldier’s salt pay was docked if he did not work hard.

Another important salt route across Europe was the Old Salt Road. This path ran 62 miles from Lüneburg in northern Germany, which was one of the most plentiful salt sources in northern Europe, to Lübeck on the north German coast. During the Middle Ages, this route became vital for providing salt for the fishing fleets that left Germany for Scandinavia, as the crews used salt to preserve the precious herring catch. It would take a cart delivering salt some 20 days to traverse the Old Salt Road, and many towns along the way grew wealthy by levying taxes and duties on wagons as they passed through.

7. The Trans-Saharan Trade Route

The Trans-Saharan Trade Route from North Africa to West Africa was actually made up of a number of routes, creating a criss-cross of trading links across the vast expanse of desert. These trade routes first emerged in the fourth century CE. By the 11th century, caravans composed of more than a thousand camels would carry goods across the Sahara. Gold, slaves, salt, and cloth were traded along the route, as were objects like ostrich feathers and European guns.

The trade route was instrumental in the spread of Islam from the Berbers in North Africa into West Africa, and with Islam came Arabic knowledge, education, and language. The Trans-Saharan trade route also encouraged the development of monetary systems and state-building, as local rulers saw the strategic value in bringing large swathes of land, and thus their commodities, under their control. By the 16th century, as Europeans began to see the value in African goods, the Trans-Saharan trade routes became overshadowed by the European-controlled trans-Atlantic trade, and the wealth moved from inland to coastal areas, making the perilous desert route less attractive.

8. The Tin Route

From the Bronze Age to the Iron Age, the Tin Route was a major artery that provided early settlements with access to a vital ingredient for metal-making: tin. Copper must be alloyed with tin to make bronze, an advance that occurred in the Near East around 2800 BCE and created a stronger, better metal than the type used previously. This new technology created a demand for tin, and as it is not found in many places, the resource became an important item for trade.

One such tin route flourished in the 1st millennium BCE. It stretched from the tin mines in Cornwall in the far southwest of Britain, over the sea to France, and then down to Greece and beyond. Evidence for this route is provided by the many hillforts that sprung up along the way as trading posts. Historians believe trade passed both ways up and down this route, as the hillforts provide evidence of exotic artifacts, including coral and gold. No written accounts survive from this period, but the archaeological record shows technology and art traveled the route between northern Europe and the Mediterranean alongside tin—thus providing a vital link across Europe.