Drawing Lines on Water: Tordesillas and Zaragoza

Episode Narrative

In the year 1492, the world stood on the brink of profound transformation. A fleet of three ships, commanded by Christopher Columbus and sponsored by the Spanish crown, set sail across the Atlantic. Their destination was far and uncertain, but their ambition was clear: to find a new route to the riches of Asia. Instead, they encountered a vast, uncharted expanse of land. Columbus’s arrival in the Caribbean initiated sustained European contact with the Americas, a moment that marked not only a new chapter for Europe but a cataclysmic upheaval for the Indigenous peoples who had inhabited these lands for millennia.

As Columbus planted the Spanish flag in the unfamiliar soil, he unwittingly sparked a scramble for territorial claims that would require formal demarcation — lines drawn not on maps but in the lives and cultures of those who called this land home. The first echoes of conflict emerged almost immediately as desires for power, land, and resources collided with existing Indigenous sovereignties. The world was changing, but who would define the rules of its new order?

One year later, in 1493, Pope Alexander VI intervened, issuing the papal bull *Inter caetera*. This decree drew a north-south line, a piece of parchment geography that stretched 100 leagues west of the Azores and Cape Verde Islands. It effectively granted Spain rights to all lands west of the line and Portugal rights to those to the east. Yet, this division was not just a relic of papal power; it ignored the complex tapestry of Indigenous nations that existed at the time. The threads of their lives were not easily severed by paper or decree. Immediate disputes arose, igniting a fire that would seek to consume nations.

The Treaty of Tordesillas followed in 1494, a product of negotiation between Spain and Portugal to adjust the original papal line, moving it 370 leagues further west. The implications were vast and unanticipated, especially when the eastern bulge of South America — which we now know as Brazil — was discovered, falling within Portuguese claims. As Portuguese navigators charted these new waters, the map of the world became a source of invention and, devastatingly, division.

Fast forward to 1513, and Vasco Núñez de Balboa became the first European to lay eyes on the Pacific Ocean from the Americas. This monumental sight not only expanded the horizons of European ambition but complicated the application of the Tordesillas line in the context of a continent teeming with life and cultures that were far more intricate than the colonizers could understand. The vastness of what lay before them prompted a deep consideration: how could one line adequately capture such complexity?

In the years that followed, the Magellan-Elcano expedition from 1519 to 1522 completed the first circumnavigation of the globe, proving that Earth was indeed spherical and revealing the difficulty of imposing clear divisions upon a world of such scale. The very concept of dividing the globe along a single meridian began to unravel, exposing the impracticality of a system built on parchment and power.

Attempts continued to impose order in this age of imperial ambition. In 1529, the Treaty of Zaragoza sought to extend the logic of Tordesillas into the Pacific, drawing yet another line of demarcation, this time near the Moluccas. However, the quest for accurate measurements of longitude at sea thwarted effective governance. Overlapping claims persisted, echoing the chaos that had emerged globally.

By the mid-1500s, Spanish and Portuguese cartographers worked diligently to craft increasingly detailed maps, yet these often mirrored imperial aspirations more than geographic reality. Borders shifted, redefined by explorers who “discovered” new territories, while the resistance from Indigenous nations remained often uncharted. Amidst this ongoing conflict, the Spanish Crown attempted to regulate the situation on the ground. In 1542, it issued the New Laws, which sought to address the treatment of Indigenous peoples and curb the excesses of the *encomienda* system. Yet local authorities often turned a blind eye, ignoring or subverting the intentions of these reforms.

As the late 1500s rolled in, Spain fortified its presence in the Americas through a network of port cities such as Havana, Cartagena, and Veracruz. These cities became hubs of military and commercial activity, blending purpose and power. Here, the forces of colonialism forged a new kind of landscape, one where the vibrant lives of Indigenous peoples were further suppressed.

In the decade that followed, the Spanish Crown reorganized its empire into two viceroyalties — New Spain and Peru — each ruled by a viceroy. These bold administrative borders rarely respected Indigenous territories or ecological zones, solidifying colonial ambitions on anyone but the Spanish crown. Meanwhile, the Iberian Union from 1580 to 1640 temporarily aligned the Spanish and Portuguese crowns, blurring colonial borders in the Americas and prompting increased smuggling and unofficial settlements. The Río de la Plata became a hotbed of such activity, revealing the porous nature of imperial control and reinforcing the notion that these drawn lines were not easily maintained.

As the early 1600s approached, Jesuit missions emerged as a complex institution within South America. They created semi-autonomous Indigenous communities, occupying a delicate balance between colonial control and native autonomy. These communities often resisted both Spanish and Portuguese encroachment, further complicating the already tangled fabric of colonial rule.

Environmental factors also played a crucial role; a major drought impacted North America in 1610, affecting both Indigenous and colonial societies. This shared vulnerability to nature laid bare the harsh realities of life in this new world and the tenuousness of emerging colonial settlements.

In the following decades, other European powers — Dutch, English, and French — began to challenge Iberian dominance. They established colonies throughout North America and the Caribbean, resulting in a tapestry of European enclaves that further complicated the mapping of the Americas. The power dynamics shifted, and the landscape of colonialism became ever more complex.

By 1640, Portugal regained independence from Spain, reigniting border conflicts, particularly over the disputed region of Colonia del Sacramento in modern-day Uruguay. This area became a flashpoint, embodying the insecurities and tensions that would characterize the colonial landscape for more than a century.

As the late 1600s unfolded, the transatlantic slave trade intensified, forcibly relocating millions of Africans to the Americas. In doing so, it created new cultural and demographic borders within colonial societies, further deepening the complexities of human life in this newly formed world.

The dawn of the 18th century brought with it the *Bourbon Reforms*, initiated by the Spanish Crown in 1700. These reforms aimed to centralize colonial administration, tighten border controls, and remove unauthorized settlers — particularly Portuguese — from contested regions like the Amazon and Río de la Plata. Yet, as borders tightened administratively, the realities on the ground remained far more convoluted.

In 1750, the Treaty of Madrid sought to redraw South American borders based on the principle of *uti possidetis*, or actual possession. This treaty acknowledged Portuguese control over much of the Amazon and interior Brazil, yet the new lines ignited local resistance, leading to further disputes. By 1777, the Treaty of San Ildefonso tried to address lingering border issues between Spain and Portugal, but ambiguities persisted, especially in remote regions where Indigenous peoples maintained de facto autonomy.

As the 18th century drew to a close, the once-clear lines established by Tordesillas and Zaragoza evaporated, dissolving into a mosaic of colonial claims and Indigenous territories. This tumultuous backdrop set the stage for the independence movements that followed and the border wars of the 19th century.

In reflecting upon this turbulent period, one question lingers: how can humanity learn from this history of division and conflict? The lines that were once drawn on water, seen as mere boundaries separating competing empires, now echo as reminders of the lives and cultures forever altered by imperial ambition. The struggle for identity, autonomy, and recognition remains enduring, a testament to the complexity of drawing lines — be they upon maps or in the hearts of people. As we confront the legacy of this age, we must ponder how borders shape our present and how the threads of history bind us all.