Causes case study — the Spanish conquest of the Aztec and Inca empires (History HL)

The big idea: Between 1519 and 1572, small Spanish forces destroyed two of the largest empires in the Americas — the Aztec Empire and the Inca Empire.

This is your Americas case study: the same long-term/short-term/spark framework applies, but the causes here are tangled up with religion, gold, and conquest in a way no European war is.

In 1519 the Spaniard Hernán Cortés landed on the coast of Mexico with a few hundred men and marched inland to Tenochtitlan, the Aztec capital, a lake-city bigger than most of Europe's.

Thirteen years later, in 1532, another Spaniard, Francisco Pizarro, landed on the coast of Peru and marched into the heart of the Inca Empire, which stretched thousands of kilometres down the Andes.

Why so few Spaniards could win: Long-term causes explain why conquest was even possible — Spanish steel, horses, and guns, and diseases like smallpox that killed huge numbers of indigenous people who had no immunity.

But causes are not only about weapons. Ideology, economics, and politics all pushed the Spanish to invade — and political division inside both empires gave them the opening they needed.

Why examiners set this case study: This is a genuine non-European war, so it satisfies the 'at least two regions' rule on its own if paired with a European case study like the Thirty Years' War.

It also lets you show the same causal framework — long-term causes, short-term causes, and a spark — applied outside Europe, which is exactly what a top-band essay needs to demonstrate.

Spain's kings did not send conquistadors across the ocean for one simple reason. Historians often sum up Spanish motives with three words: God, gold, and glory. Let's take each in turn.

1 · Religious and ideological causes: Spain had just finished the Reconquista in 1492, driving out the last Muslim kingdom. This left Spain with a powerful sense of religious mission.

The Spanish crown and the Catholic Church wanted to convert indigenous peoples to Christianity, and conquistadors used this as moral justification for invasion and for destroying temples and religious practices they saw as pagan.

2 · Economic causes: gold and silver: Spain's crown was heavily in debt from European wars, and conquistadors themselves were often minor nobles with no land or fortune at home.

Rumours of fabulous wealth drove them onward — the myth of El Dorado pulled expedition after expedition deeper into unknown territory.

The economic prize was real, not just legend. The Aztecs had gold jewellery and tribute stores that Cortés seized and melted down.

Even more valuable in the long run were the silver mines the Spanish later found in the Andes, especially at Potosí, which financed the Spanish empire for two centuries.

Don't treat 'God, gold and glory' as separate boxes: These causes were tangled together. Converting indigenous peoples justified seizing their wealth; seizing wealth funded further religious missions; and both fed the conquistador's hunger for personal glory.

A strong essay shows how the motives reinforced each other, rather than listing them side by side.

Personal ambition and indigenous politics turned two risky invasions into astonishing victories. Without political division inside the Aztec and Inca empires, a few hundred Spaniards would likely have failed.

3 · Personal ambition: Cortés and Pizarro: Both conquistadors were driven by personal glory as much as by crown orders. Cortés defied his governor in Cuba to launch his expedition; Pizarro had failed twice before succeeding on his third attempt to reach Peru.

Each man wanted the fame and title that would come from conquering an empire — a very personal, political motive layered on top of Spain's wider aims.

4 · Exploiting the Aztec tributary system: The Aztec Empire was not one united nation — it was a network of conquered city-states forced to pay tribute to Tenochtitlan.

Many subject peoples, above all the Tlaxcalans, deeply resented Aztec rule. Cortés allied with tens of thousands of Tlaxcalan warriors, turning his invasion into a civil war the Spanish exploited rather than a war they won alone.

5 · Exploiting the Inca succession war: The Inca Empire was in the middle of a bitter civil war when Pizarro arrived. Emperor Huayna Capac had died of smallpox (spread ahead of the Spanish themselves), and his two sons, Huascar and Atahualpa, fought a destructive war over the throne.

Atahualpa had just won this war when Pizarro captured him in 1532 at Cajamarca — the empire was exhausted and divided exactly when it needed to be strong.

The examiner's favourite point: The best answers explain why so few Spaniards beat such large empires — and the answer is political division, not just steel and horses.

Without the Tlaxcalans and without the Inca civil war, both conquests could easily have failed.