How Maritime Trade Forged Global Culture: From Disease and Spices to Religion and Law

The myriad things that people carried, inadvertently and otherwise, from place to place in the course of trade, migration, conflict, and other undertakings had a transformative effect on culture as well. When we talk about maritime exchange and its cultural implications, we must keep in mind the three broad categories of things involved: living things, including people and other animals, plants, and disease; inanimate objects, from minerals and harvested crops to manufactured goods and prepared foods; and the intangible products of human intellect and imagination—language, literature, and artistic style; religion and law; modes of governance and social organization; ways of doing business; and even biases and taboos.

Living things are among the most easily assimilated into host cultures, although, as the phrase “invasive species” suggests, they can disrupt or transform ecosystems and the human societies that depend on them, even when their effects are apparently benign. Many of the foods that we associate today with particular geographic regions originated in completely different parts of the world. Sugar grew first on the island of New Guinea and was gradually traded westward, to Southeast Asia, India, and Southwest Asia, where Europeans encountered it for the first time during the crusades starting at the end of the eleventh century. It was among the first commodities exported to the Americas in the sixteenth century, and Caribbean sugar plantations were so important to Britain’s economy that during the American Revolution George III insisted that “the islands must be defended, even at the risk of an invasion of this island” (Paine 2013: 485).

Foodways across much of tropical Africa changed with the introduction of three crops that originated on or near the island of New Guinea. Taro is one of the world’s oldest cultivated crops, identified in archaeological contexts from the Solomon Islands from 28,000 years ago. The earliest long-distance voyagers in the Pacific carried it with them as they settled the innumerable islands of Oceania to the south and east starting in about 1500 BCE. At some point during the first millennium CE, taro, the banana, and the purple yam were introduced to sub-Saharan Africa, where they became culinary staples. Cultivation of these three crops was carried westward across Africa, and with the coming of the slave trade in the sixteenth century, they were transplanted to the American tropics, where they became comparably important foods.

Diseases were the most destructive and culturally transforming living things of the “Columbian exchange,” the process by which animals, plants, and bacteria moved between Eurasia/Africa and the Americas and Pacific Islands in the fifteenth and sixteenth centuries. The introduction of Eurasian and African diseases to susceptible populations of the Americas led to catastrophic and wholly unanticipated loss of life—more than 80 percent (some estimates put the figure at 95 percent) of the population—and the consequent eradication of entire states and cultures. This demographic devastation, coupled with the survivors’ lack of familiarity with newly introduced crops (such as wheat and sugarcane) and livestock (cattle, pigs, and sheep), was a primary driver of the slave trade, which saw nearly eleven million people forcibly carried from Africa to the Americas between the 1520s and 1860s.

The spread of disease by ship was not unique to the period of European expansion. In the 1340s, a Genoese vessel carried the plague (which had taken decades to cross Central Asia overland from China or Korea) from a Black Sea port to Italy and from there around Europe, where an estimated twenty-five million people—between one-third and one-half of the population—died within a few years. Akira Yoshimura’s novel Shipwrecks (1982) is an affecting account of the effects of a shipborne disease on a remote fishing community in early coastal Japan.

The effects of transplanting crops, people, and other animals were not always negative. Coffee (native to the highlands of Ethiopia) and bananas are among the primary exports of Central and South America, and cattle and wheat (first domesticated in southwest Asia) are pillars of the North American agricultural economy. Before the European American settlement of the Great Plains in the 1800s, the mounted warriors of the Comanche, Apache, and Kiowa were considered among the finest light cavalry in the world. Yet, fighting on horseback was a newly acquired talent for Native Americans, whose horses were descended from animals brought by Spanish conquistadors that had escaped into the wild. Domesticated anew, they gave Plains Indians a previously unimaginable mobility. Elsewhere, Australia and New Zealand have the second and seventh largest populations of sheep in the world, respectively, although sheep were introduced in the late 1700s. Similarly, New Zealanders only began growing Chinese gooseberry in the 1900s and gave it the name kiwifruit, or kiwi, to help boost exports in the 1960s.

Considering American transplants to the rest of the world, potatoes and tomatoes were unknown in Eurasia before the sixteenth century. Yet who today can imagine Italian cuisine without the tomato, which until then was unknown outside of western South America and Central America? The long-term cultural effects of the diffusion of different crops around the world are not just culinary. Originally domesticated in the Peruvian highlands, the potato was introduced to Europe in the mid-1500s to scant acclaim. But as “an easily raised, nutritionally adequate and abundant food” (Salaman 1949: 335) that could feed livestock as well as people, in the 1600s the potato was readily embraced by an Irish peasantry devastated by a century of wars. Over reliance on the potato made the general population susceptible to any failure of the crop, a not infrequent occurrence.

The most devastating instance was the Great Hunger of 1845 to 1852, when Ireland’s population fell by roughly 30 percent, half lost to starvation and disease, the remainder to overseas emigration. The overwhelming majority of emigrants went to the United States—1.7 million in the 1840s and 1850s—but the Irish formed a significant proportion of the immigrants to Britain, Canada, and Australia as well. Thus, 250 years after the haphazard introduction of the potato, the failure of the crop would “have the most far- reaching effect on the future of Ireland and, indeed, Western civilization” (Salaman 1949: 214), as the people of a small, impoverished country on the western fringe of Europe came to exercise an influence in world history that owed little to native industry or commercial enterprise.

If the role of the potato in the Great Hunger exemplifies an unintentional large-scale cultural transformation resulting from maritime commerce, the deliberate effort to transplant breadfruit from Tahiti to the Caribbean yielded a different outcome. In the 1770s, British plantation owners proposed bringing breadfruit trees from Tahiti to the West Indies to be grown as food for slaves. It took two separate voyages over five years for William Bligh to complete the mission. Yet although the trees thrived in their new environment, breadfruit itself proved an acquired taste. By the time it caught on, forty years later, the British had abolished slavery and with it the whole rationale for the undertaking. Yet the effort gave rise to one of the most enduring and popular stories in maritime literature, that of the mutiny on the Bounty, the first ship sent to Tahiti in 1787.

Shortly after sailing from Tahiti with more than 1,000 trees aboard, Bligh’s second in command, Fletcher Christian, seized the ship and forced Bligh and 19 shipmates into a 23-feet-long launch with enough food and drink to last a week. The following day, one of the crew was killed when the castaways landed on a nearby island. Bligh then determined to sail straight for the Dutch settlement on the island of Timor, 3,600 all but uncharted miles to the west. They arrived forty-three days later with not a man lost. Following his return to England, Bligh was given a second chance to complete his mission, which he did, in 1792. Christian and company had meanwhile returned to Tahiti, where they recruited some islanders, including women, before sailing into the vast Pacific to the tiny (4.5 km²) remote island of Pitcairn in early 1790. Despite concerted efforts to find and punish the mutineers, it was not until 1808 that an American sealer called at Pitcairn, and it was another thirteen years before a British ship reached there.

The dissemination of living things via maritime trade was often an unintentional consequence of maritime enterprise, as in the case of disease. In other cases, people carried crops and animals from home because they were familiar. If they found a welcoming environment (and they didn't always), so much the better. Yet other cultural transformations were a by-product of the more deliberate search for inanimate things—the sorts of goods we associate with a globalized economy today.

Chinese pottery has been a staple of long-distance sea trade for more than 1,000 years. Dating to the early 800s, the so-called Belitung ship (see entry) was built in Southwest Asia, which sank in the Java Sea while en route from China with a cargo that included some 60,000 mass-produced bowls, inkpots, spice jars, and ewers, and other pieces made in Changsha, in landlocked Hunan Province. The existence of the ship is proof of international sea trade 1,100 years ago, but what is most striking is the choice of decorative motifs employed by the Chinese potters, which testifies to a keen understanding of their intended markets. Most of the bowls bear geometric or naturalistic designs or inscriptions from the Quran rendered in red and green and were obviously destined for markets across the sprawling Abbasid Caliphate.

Smaller numbers of green-splashed bowls were destined for Iranian buyers, whereas those adorned with lotus symbols were intended for Buddhist customers. The sensitivity of the landlocked Chinese potters to their customers’ cultural expectations for ceramics that originated thousands of miles away is remarkable. Such a phenomenon recurred starting in the sixteenth century, when the Chinese began making porcelain for export to Europe, often in forms formerly unknown to them but based on European samples.

What had brought Europeans to Asia in the first place was spices, the most alluring of which were cloves, nutmeg, and mace from the diminutive Spice Islands of Maluku in eastern Indonesia. Sought as much for their medicinal as for their culinary uses, spices had long been a driver of seaborne trade within Asia. Nutmeg was valued for providing gastrointestinal relief, and perhaps as a mild hallucinogen, and cloves have anesthetic and, purportedly, aphrodisiac properties. But the propagation of spices also transformed culinary traditions, as we know from a seventh-century monk who disdained a Chinese cuisine that was heavy on “fish and vegetables mostly uncooked,” in contrast to the more lavish culinary arts of India where “all vegetables are to be well cooked and to be eaten after mixing with the asafetida, clarified butter, oil, or any spice” (Paine 2013: 306). The drive to secure monopolies on spices especially transformed European economies, gave rise to the establishment of non-native groups—not just Europeans but also Chinese, Indian, and others—throughout Southeast Asia, and laid the foundation for the oppressive European imperialism of the nineteenth and twentieth centuries, which encompassed most of coastal Asia and Africa.

Inanimate Goods. Language, religion, and law (the last of which often derives from religion) are excellent markers for where maritime exchange took place, especially in the absence of explanatory written records. Among the most revolutionary developments in the ancient Mediterranean was the diffusion of a written alphabet from Phoenicia, the coast from what is now Palestine in the south to Syria in the north. The oldest Phoenician writings have been found not in the Levant, but along trade routes from the Levant to as far west as Sardinia. Maritime traders of the ninth century also carried the alphabet to Greece, whose people made it their own. With these letters—the last word in low-volume, high-value cargos—the Greeks created the most diverse and influential body of literature in the ancient world, one that embraced philosophy, science, medicine, history, oratory, poetry, and drama, and the preservation of which has been the basis for countless cultural revolutions in the thousands of years since.

In Asia, the first religion to be widely diffused by sea trade was Hinduism, which reached the mainland and islands of Southeast Asia more than 2,000 years ago. Buddhism was originally introduced to China via the overland Silk Road, but it was reinforced by seafaring monks who carried their religion to Southeast Asia, China, Korea, and ultimately Japan. China’s embrace of Buddhism led to changes in the nature and scope of long-distance sea trade. There was a new emphasis on religious artifacts, from relics to incense, and an increase in the movement of scholars, monks, and translators. Unlike Confucianism, with its elitist tendencies (or Hinduism, with its rigid caste structure), Buddhism was accessible to all. This gave merchants a bigger market to satisfy, especially as goods like incense became secularized and desirable even among non-Buddhists.

Somewhat later, Islam spread as far as modern Pakistan, where it stalled in its eastward overland advance in the eighth century. However, Muslim seafarers established enclaves along the west coast of India, as well as in pockets of what is now Indonesia (which is now the country with the world’s largest Muslim population), Vietnam, and the coast of China, while to the west they launched a Muslim diaspora along the coast of East Africa from Somalia to Mozambique. True faith is powerful, but there is no gainsaying that the promulgation of religion owes much to traders and is often facilitated by commercial self-interest. For traders everywhere, the profession of a common religion facilitated transactions and increased trust.

A story in Buzurg ibn Shahriyar al-Ramhormuzi’s tenth-century Book of the Wonders of India relates how a trader from Oman named Ismail kidnapped an unnamed ruler from what is now northern Mozambique and sold him into slavery. The captive king converted to Islam and escaped his owner by joining pilgrims bound for Mecca, from where he went to Cairo. He eventually returned home and resumed the throne. Ismail had continued his trade and eventually found himself in front of his erstwhile prisoner, who forgave him “because you were the first cause of the purity of my religion.” Sending him on his way, the king asked Ismail to “let Muslims know that they may come here to us as to brothers, Muslims like themselves.” The king’s refusal to avenge his kidnapping testifies to his reverence for Islam, but his people’s adoption of the alien religion had a practical side, and they could promote their new faith in the same way a business might post a sign saying, “Arabic spoken here” (Buzurg 1981: 31-6).

In a similar vein, a century before Ismail, St. Ansgar, known as the Apostle of the North, preached Christianity to the Danes for the first time. He was successful in part because the king allowed him to build a church at the port of Hedeby, “near to the district where merchants from all parts congregated.” As in the case of Buzurg’s unnamed king, a willingness to accept Christianity was profitable, and thanks to Ansgar’s evangelizing, Frisian, Frankish, and other Christian merchants “made for the place readily and without any fear—something which was not possible previously” (Rimbert 1921: 84).

Religion manifests itself in people’s culture not only in its practice and ritual but also in its laws, many of which derive from religious precepts. Some of these actively inhibit commercial (and thus cross-cultural) exchange, and religious strictures proved a significant obstacle to the trade of the medieval Mediterranean. Judaism, Christianity, and Islam all proscribed lending money at interest to coreligionists, and it was not until the eleventh century that merchants had devised contractual forms that promoted growth without violating religious law. These provided a major impetus for the so-called commercial revolution that underlay the growth of Mediterranean trade between the eleventh and thirteenth centuries. It is no coincidence that this was the era of the Crusades, which were sustained by maritime lifelines between the Middle East and Western Europe, and during which Europeans were first exposed to the Eastern exotics that would later fuel their interest in overseas expansion.

Intangible Goods. European expansion ushered in a new era in world history, in part because between the sixteenth and nineteenth centuries, Europeans disseminated worldwide a variety of cultural and legal novelties that many now take for granted. Among these was the notion that political control could be exercised over the oceans. Although states had used their navies to extend their authority overseas—to seize islands, or to control strategic passages and choke points—no one had ever presumed to divide the sea preemptively and to treat it as a political space analogous to territory on land. The Romans had called the Mediterranean Mare Nostrum, “Our Sea,” but that was a simple statement of fact. Classical jurisprudence actually regarded the sea as a global commons, the property of all people.

By the thirteenth century, Genoa and Venice were asserting their jurisdiction over adjacent seas in the Mediterranean as a justification for taxing trade. The greatest change came in the fifteenth century, when various popes began issuing bulls (decrees) and mediating treaty negotiations in which Portuguese and Spanish asserted jurisdiction over lands not already ruled by Christians. In essence, the Spanish had the right to explore to the west, and the Portuguese to the east, of a line drawn down the middle of the Atlantic. In the Western Hemisphere, this gave the Spanish the right to virtually all of the Americas, apart from the eastern bulge of South America, which became Portuguese Brazil; Portugal claimed smaller territories in Africa and Asia. (The Spanish secured rights to the Philippines by a treaty of 1529 that continued the line around the other side of the world.) The Spanish focused their efforts on Central and South America, leaving North America open to Northern Europeans, especially the English and French. These papally sanctioned divisions help explain why, 500 years later, English, Spanish, French, and Portuguese are official languages in nearly 120 countries worldwide, and Christianity is the majority religion in more than 120.