Rome and the Silk Road
Rome and China never met. The two largest empires of the ancient world existed simultaneously — the Han dynasty and the Roman principate overlapped for roughly two centuries — and the goods they produced circulated between them across thousands of kilometers of overland and maritime routes. But no Roman diplomat reached Chang’an, and no Han envoy arrived in Rome, and what each knew of the other was filtered through so many intermediaries that the images were almost entirely mythological. Rome called China Serica, the land of silk. China called Rome Daqin, the Great Qin, imagining it as a mirror-image empire on the far western edge of the world. The distance between them was too great and the intermediary interests too profitable for direct contact to develop.
The trade that connected them was enormous, persistent, and consistently alarming to Roman moralists who calculated what it was costing. Silk was the primary commodity moving westward: produced in China, processed and traded through Parthian and later Sassanid Persia, carried by Sogdian merchants across Central Asia, and delivered eventually to Roman markets where it commanded prices sufficient to provoke senatorial legislation against its use. Roman men wearing silk were a recurring target of sumptuary moralizing — silk was effeminate, silk was foreign, silk was bankrupting Italy. The legislation accomplished nothing. Roman demand for silk was inelastic enough to sustain overland trade across the most difficult terrain in the world.
What moved eastward in exchange was primarily gold and silver coinage, glassware, and certain Mediterranean luxury goods. The trade imbalance — more precious metal going east than goods coming west — was noted by Pliny the Elder, who calculated the annual drain on Roman currency at several hundred million sesterces and blamed Roman luxury consumption for the damage. Modern economists are skeptical of Pliny’s arithmetic but not his direction: the flow of coinage eastward was real and left archaeological evidence in the form of Roman coins found at sites across India, Southeast Asia, and beyond.
The maritime route through the Indian Ocean was at least as important as the overland Silk Road and substantially faster. The discovery — or more precisely the systematic exploitation — of the monsoon wind pattern by the first century BC allowed Roman-era merchants to make the round trip from Red Sea ports to the Indian subcontinent in a single season. Ports like Berenice on the Egyptian Red Sea coast and Barygaza on the Indian coast facilitated a trade in spices, textiles, gemstones, and pepper that was substantial enough to generate considerable documentary evidence: the Periplus Maris Erythraei, an anonymous merchant’s guide to Indian Ocean trade dating to roughly the first century AD, provides a practical account of ports, commodities, and sailing conditions that reads like a trade manual because that is what it was.
Pepper was possibly the most economically significant commodity in this trade, more important in volume and value than silk. The Roman demand for black pepper as a flavoring and preservative was enormous; Attila the Hun reportedly demanded three thousand pounds of pepper as part of his ransom for Rome in 408 AD, which suggests something about its perceived value as a luxury commodity even at the moment of the Western Empire’s military crisis. The spice trade funded the port cities of southern Arabia and the trading communities of the Malabar Coast for centuries.
The intermediaries who controlled the overland routes — Parthian Persia, then Sassanid Persia — understood their position and exploited it. Direct Roman access to Central Asian trade was blocked by the Parthian empire and its successors, who collected tolls and markups on everything that passed through their territory. Roman attempts to bypass this position — through the Red Sea maritime route, through diplomatic contact with kingdoms on Persia’s periphery — were persistent and never entirely successful. The Parthian and Sassanid empires had a structural interest in maintaining their intermediary role, which gave their periodic wars with Rome an economic dimension beyond the territorial and dynastic causes that the ancient sources emphasize.
The trade networks that connected Rome to the East survived Rome itself. When the Western Empire dissolved in the fifth century, the commercial relationships that had developed over centuries did not immediately disappear. Byzantine merchants, Sogdian traders, and eventually Arab networks maintained connections between the Mediterranean and the Asian trading world in forms that the Roman Empire had initiated. The Silk Road is named for a commodity, but it was really an infrastructure — of routes, credits, relationships, and knowledge — that no single empire created or destroyed. Rome built one end of it and benefited from it for centuries. The infrastructure outlasted the empire that had used it, which is a reasonable description of Rome’s relationship to most of the world it touched.