The Cartographic Revolution of the Age of Exploration

The Age of Exploration, spanning roughly from the early 15th to the late 17th century, was a period of profound transformation in how Europeans understood and depicted the world. Maps from this era are far more than mere navigational tools; they are complex artifacts that blend empirical observation, political ambition, religious ideology, and artistic imagination. Among the most revealing elements of these maps are the borders and labels they employ. Borders during this time were rarely precise lines based on surveyed boundaries. Instead, they reflected the territorial claims of burgeoning European empires—Portuguese, Spanish, English, French, and Dutch—who were often competing for the same lands and trade routes. Labels, meanwhile, served multiple functions: they identified known regions, staked political ownership, marked areas of commercial interest, and sometimes perpetuated myths about distant lands and their inhabitants. Understanding the fascinating facts behind these borders and labels is essential to appreciating how cartography shaped—and was shaped by—the course of history.

Historical Context of Borders in Early Modern Cartography

The concept of a fixed, measurable border between territories is largely a modern invention. In the 15th and 16th centuries, borders on maps were often speculative, derived from a combination of ancient authorities, fragmentary exploration reports, and wishful thinking. European powers used maps to assert claims over vast, often unexplored continents. A border on a map from 1550 might represent a line drawn in a treaty room rather than on the ground, with no regard for the actual geography or the people living there.

The Treaty of Tordesillas: A Line in the Atlantic

One of the most famous—and factually fascinating—borders in exploration cartography is the Line of Demarcation established by the Treaty of Tordesillas in 1494. This treaty divided the newly discovered lands outside Europe between Portugal and Spain along a meridian 370 leagues west of the Cape Verde islands. On maps, this line was often drawn as a prominent vertical divide, splitting the Atlantic Ocean and later South America. The treaty’s border was inherently speculative; no one knew exactly where the line fell across the unknown interior of the Americas. Yet cartographers dutifully rendered it, giving the illusion of precise control. This border had enormous consequences: it granted Brazil to Portugal and the rest of the Americas to Spain, shaping the linguistic and cultural map of the continent for centuries. For a deeper look at the treaty’s cartographic implications, see the Library of Congress’s digitized 1502 Cantino planisphere, which is one of the earliest surviving maps to show the demarcation line.

Fluid and Contested Borders in the East Indies

In Southeast Asia and the East Indies, borders were even more fluid. European mapmakers often drew vague, dotted lines to separate the “spheres of influence” of competing trading companies like the Dutch East India Company (VOC) and the British East India Company. These lines were less about political sovereignty and more about commercial monopoly. A map might label the Spice Islands (Maluku) as belonging to the Portuguese or later the Dutch, but the actual control was contested and changed frequently. Borders could shift with each new voyage or treaty, and cartographers had to update their plates—or risk producing maps that were politically obsolete. This dynamic is well captured in Mercator’s 1595 atlas, which shows evolving labels for the Indonesian archipelago as Dutch influence grew.

Labels and Their Significance

Labels on Age of Exploration maps are treasure troves of information about contemporary knowledge, biases, and aspirations. They were not neutral descriptors. A label could assert a political claim, evoke a mythical past, or warn of danger. Mapmakers had to decide what to name lands, seas, and peoples, often with very little reliable data.

Political and Proprietary Labels

Many labels were overtly political. Spanish maps would label the Gulf of Mexico as “Mar del Norte” (Sea of the North) or “Mar de las Indias”, while Portuguese maps might refer to the same waters with different names. Large swaths of North America were labeled “Nova Francia” (New France) or “Virginia” (often written in elaborate script to honor the Virgin Queen Elizabeth I). In South America, labels like “Peru” and “Brazil” implied Spanish and Portuguese sovereignty, even though interior regions were entirely unknown. These labels were tools of empire: they made claims visible and, in the minds of European courts, legitimate.

Mythical and Exaggerated Labels

The limited knowledge of cartographers gave rise to some of the most fascinating labels in cartographic history. The landmass Terra Australis Incognita appeared on maps for centuries, labeled with the Latin phrase meaning “unknown southern land.” It was drawn as a huge continent stretching across the bottom of the world, complete with borders and place names like “Psittacorum Regio” (Region of Parrots) and “Beach” (often thought to be a corruption of the Venetian Marco Polo’s “Locach”). Similarly, the Pacific Ocean was dotted with labels for “Isla de la Conversión” (Island of Conversion) or “Rica de Oro” (Rich in Gold), islands that never existed but were eagerly sought by explorers.

Religious and Cultural Labels

Religious fervor also influenced labeling. Maps from the Spanish and Portuguese empires often included labels such as “Tierra de la Santa Cruz” (Land of the Holy Cross) for Brazil, or “Nova Hispania” (New Spain) to emphasize the Christianization of the New World. Areas controlled by non-Christian peoples were sometimes labeled with derogatory or exoticizing terms: “Land of the Anthropophagi” (cannibals) or “Barbary” for North Africa. These labels reinforced narratives of European superiority and the supposed need for missionary work and colonization. The New York Public Library’s archive of early modern maps includes several examples where labels like “Here be Dragons” (a phrase rarely actually used) were replaced with more specific, often terrifying, descriptions of native ferocity.

Common Features of Exploration Maps: More Than Meets the Eye

Beyond borders and labels, Age of Exploration maps shared a set of visual conventions that modern viewers often misinterpret. Understanding these common features reveals the cartographer’s intent and the limitations of the era.

Decorative Cartouches

Cartouches—ornate frames surrounding map titles, dedications, or legends—were far more than decoration. They were opportunities for political propaganda. A cartouche might depict a European monarch receiving tribute from native peoples, or show allegorical figures representing the continents. For example, a 17th-century Dutch map of the Americas might include a cartouche featuring a crowned woman symbolizing Europe holding a globe, with a Native American figure at her feet. The borders of the cartouche itself often echoed the shape of the territories being claimed, reinforcing the message of ownership. Cartographers used cartouches to flatter patrons and justify exploration as a noble, even divine, mission.

Mythical Creatures and Sea Monsters

The sea monsters and strange beasts that fill the oceans and unexplored interiors of these maps are frequently described as mere decoration. But many had symbolic or informational purposes. A kraken or giant serpent in the North Atlantic warned sailors of dangerous waters. A unicorn or a giant bird on a landmass might indicate a region where myths were believed to be reality. The famous Carta Marina (1516) by Waldseemüller includes a sea monster labeled “Hic sunt dracones” (Here are dragons), one of the very few historical uses of that phrase. These creatures also reflected the mapmaker’s reliance on classical texts, such as Pliny the Elder’s Natural History, which described exotic beasts. Including them on a map lent authority by connecting to ancient learning.

Place Names and Nomenclature Variations

Place names on exploration maps are notoriously inconsistent. The same bay might be labeled “Baya de Todos Santos” on a Spanish map and “Havre de la Trinité” on a French one. Islands were often renamed by each explorer who sighted them; the Solomon Islands, for instance, were labeled differently on Spanish, Dutch, and English charts for decades. Some place names were phonetic transcriptions of native words, often mangled by European ears. Others were grandiloquent labels like “Nueva Extremadura” or “Nouvelle-Angoulême”, which never gained currency because they were unknown to local populations. The fluidity of place names illustrates how cartographic knowledge was fragmented and contested.

Scale Indicators and the Problem of Longitude

Scale indicators on early exploration maps were often rudimentary or entirely absent. Even when scale bars were present, they might be inaccurate because the fundamental problem of determining longitude had not been solved. A map might display a scale in leagues or miles, but the actual distances could be wildly off. For example, the Pacific Ocean was consistently drawn much wider than it really is on many 16th-century maps. This error was not corrected until the invention of the marine chronometer in the 18th century. As a result, borders drawn according to scale were themselves unreliable—a coast shown 500 miles away might be only 300. This had real consequences: ships sailing with these maps could miss landfalls by hundreds of miles, leading to false claims and tragic shipwrecks.

The Evolution of Borders: From Speculative Lines to Sovereignty

As exploration continued and colonies were established, borders on maps gradually evolved from speculative lines to more precise markers of control. This shift was driven by political necessity and cartographic improvement.

The Rise of Colonial Administration Maps

By the mid-17th century, colonial administrations began commissioning surveys and maps to define boundaries for tax collection, resource extraction, and settlement. French maps of New France (Canada) included borders that separated fur-trading territories from those of the British and Iroquois. Spanish maps of the Rio de la Plata region delineated encomiendas—land grants to conquistadors. These borders were often drawn as bold, colored lines—red for Spanish, blue for French, yellow for Dutch—making them stand out against the largely blank interiors. The act of drawing a border on a map was itself a claim to sovereignty; it said, “this land is ours, and we will defend it.” The National Geographic article on the Treaty of Tordesillas provides an accessible overview of how these lines shaped colonial borders.

Borders and the Representation of Indigenous Peoples

One of the most overlooked facts about borders on exploration maps is how they ignored or erased indigenous territories. Native American nations such as the Iroquois Confederacy, the Aztec Empire, or the Inca Empire were sometimes labeled as “kingdoms” but were rarely given borders of their own. Instead, their lands were divided by European lines. In some maps, indigenous territories were labeled with words like “Tierra de Indios” (Land of Indians) or “Naciones Bárbaras” (Barbarian Nations), implying they were lawless spaces awaiting European order. This cartographic imperialism had lasting effects, legitimizing the dispossession of millions of people.

Labels as Instruments of Propaganda and Persuasion

Labels were also used to persuade viewers—often monarchs, investors, or settlers—that a region was valuable, safe, or in need of conversion. The careful choice of words and lettering could make a desert look like a garden or a hostile coast appear hospitable.

The Promise of Riches

Maps of South America frequently label the interior with names like “El Dorado” (The Golden One), “Laguna de Parima” (a legendary golden lake), or “Manoa” (the fabled city of gold). These labels created a rush of explorers and conquistadors, including Sir Walter Raleigh, who searched for El Dorado in the Orinoco basin. The labels persisted on maps for decades despite repeated failures to find them. Cartographers found that including such tantalizing names increased demand for their maps, as adventurers and investors were eager for any clue to hidden wealth. Borders were often drawn to include these mythic places within a particular colony, giving the owning power a claim to potential riches.

Warnings and Dangers

Conversely, some labels served as warnings. Coasts in West Africa might be labeled “Costa dos Escravos” (Slave Coast) or “Costa da Morte” (Coast of Death). These labels were not mere descriptions; they signaled to pirates, traders, and Navy captains the dangers of disease, hostile locals, or treacherous shoals. The Bay of Biscay was often labeled “Golfo de las Yeguas” (Gulf of Mares) after a shipwreck that drowned a cargo of horses. Such labels were a form of knowledge-sharing among mariners, but they also reinforced the idea that some parts of the world were inherently dangerous and in need of European domination to be made safe for commerce.

The Legacy of Age of Exploration Cartography

The borders and labels created during the Age of Exploration did not vanish when more accurate maps emerged. They became entrenched in modern state boundaries, cultural perceptions, and even place names. The lines drawn by Spanish and Portuguese mapmakers in the 1500s roughly correspond to the borders between Spanish-speaking and Portuguese-speaking nations in South America today. Labels like “Iceland” and “Greenland”—coined by the Norse and later fixed on exploration maps—have endured, even when their originals meanings are forgotten.

Lessons for Modern Map-Readers

Studying the borders and labels of early modern maps teaches us that cartography is never objective. Every map is a product of its time, embedded with the values, prejudices, and ambitions of its creators. The borders we see on maps today are the result of centuries of negotiation, war, and cartographic decisions—some based on careful surveys, others on lines drawn arbitrarily in a treaty room. The next time you look at a historical map, look closely at the labels and the borders. They are not just information; they are stories of conquest, discovery, and imagination.

For further exploration, consider visiting the David Rumsey Map Collection, which holds an extensive archive of maps from the Age of Exploration, allowing you to examine borders and labels in high resolution.