Si Sheppard – How did a few hundred Spanish soldiers topple two empires?

Dwarkesh Podcast

This episode explores the unprecedented military and diplomatic feats of Spanish conquistadors Hernán Cortés and Francisco Pizarro. It details

Key takeaways

• Hernán Cortés conquered the 6 million-strong Aztec empire in just two and a/half years despite being vastly outnumbered.
• The introduction of horses provided a decisive psychological and tactical advantage in the American interior where no native equivalent existed.

Main topics

• Conquest of the Aztec Empire
• Concentration of power in the Inca Empire

Notable quotes

My men and I suffer from a disease of the heart that only gold can cure.

Conclusion

The episode demonstrates how technological innovation, when combined w

Transcript preview

Speaker 1 (0:00) Okay, today I'm chatting with professor and military historian Cy Shepard. I want to talk to you about the conquest of the Aztec and the Inca empires because these are some of the most shocking events in human history, unparalleled among all the military and diplomatic achievements ever made. You have a few hundred conquistadors show up to a new continent they know nothing about, and within a matter of years, they subjugate empires which have millions of inhabitants in them. In the process of doing so, They are often winning battles where they are outnumbered 100x to 1, 1,000x to 1, and in many cases not even taking a single casualty. They're doing this while upwards of 99 % of their fighting forces are made up of the very natives that they're going to subjugate. And I wanted to have you on to talk about this episode. We're not going to focus on it. We'll mostly talk about the history here. People think of AI takeover as this crazy sci-fi scenario, but this would not be the first time in history that an alien force with motivations that the natives don't understand is able to use diplomatic cunning and technological advantages to outmaneuver and then take over a much larger and well-established order. And so I wanted to have you on to understand what happened here. So first, I would love to hear the stories of what did Cortez do? What did Pizarro do? How did these conquests actually go down? Okay. Speaker 2 (1:20) Thank you. It's a great pleasure to be here. And yes, we're talking about the birth of our modern world, which played out between 600 to 500 years ago and created the modern globalized community that we all participate in today. It began in the 15th century when Europe backed up against the wall of the Atlantic under immense pressure from external forces and cut off from the core economic power bases of the East, the sources of the spice and silk. that had driven the global economy historically throughout Eurasia, are finally forced to innovate. Key names like Prince Henry the Navigator of Portugal work on turning the Atlantic Ocean from a barrier into a superhighway. Generational knowledge accrued from captains reporting in on tides and wind currents and whatever land they've managed to reconnoiter, building out the map as they go along, are able to find a way around the south tip of Africa directly to India and therefore cut out the middlemen. In Spanish, meanwhile, they're heading west. We honor the story of Christopher Columbus. In 1492, he sailed the sea blue. That was entrepreneurship. This was an expedition to arrive at the oriental markets by traveling west. Of course, his figures were completely wrong, and he was saved by the fact that, unknown to him, there was an entire continent in the place where he thought Japan, China, and the Spice Islands would be. Initially, that was perceived, ironically, as a disappointment. But over time, it became increasingly apparent this was a source of potential in land, in wealth, and in people that could be exploited. A key turning point happened in 1511. when a Spanish ambitious nobleman seizes control of Cuba, de Velazquez. He sends out from this power base expeditions, exploring the coast of what we would call Mesoamerica, Central America. Later in 1518, he assigns that task to a man who he's had a somewhat tempestuous relationship with, a man named Hernan Cortes. He'd arrived. in the New World in Cuba in 1511. He had some legal training, so he served as a notary and worked his way up to being alcalde, which is chief magistrate on Cuba, but he had much greater ambition. And he takes this warrant from the governor and runs with it. He begins recruiting men to a much wider and much more ambitious goal, not just to explore the coast, but to penetrate into the interior, to find out what's there and to seize control of it. When the governor realizes what Cortes is up to, he tries to stop him. This great moment on 18th November, 1518, he arrives at the waterfront just as Cortes gets into a boat to go out to his ships offshore. And the governor calls out to him, what are you up to? And Cortes assures him, don't worry, I have this all under control. But of course, the governor had lost control at that point. Now it was Cortes' expedition. So this is the background. And again, as you say, He is literally going off the side of the map. He's entering terra incognita, unknown to Europeans previously. His political antenna, honed by years in the islands, enables him to appreciate at a very early stage that there is a significant imperial power which has hegemony here in the mainland. and that its subject peoples chafe under the authority of whoever this lord or imperial power is. He arrives in the lands of the Totonacs, who had recently been incorporated into the imperial orbit of a people who call themselves the Meika, hence Meiko as we know it, but have come down to history based on their mythical origins in a land called Aslan as the Aztecs. So for simplicity's sake, that's what we'll refer to them as. The Totonacs resented this authority as all. subjugated and subordinated peoples do. And they saw the arrival of these outsiders as a potential opportunity to throw off the authority that had been imposed on them. So having established this relationship with the Totonacs, Cortes begins to march inland. And he enters the territory of the Lashkalans, who, like an autoimmune system, immediately rallied to defeat him, to expel him from their territory. But he fights him to a standstill for such a period of time. the Lasch-Collins, and he arrived at a new kind of arrangement. The Lasch-Collins, again, appreciate his strength, his power, his potential. They swing over to his side, and will then, henceforward, serve as guides and reinforcements for his expedition deeper into the interior. Can Speaker 1 (5:45) we pause here and talk about the numbers? So how many men had Cortez brought with him? Even the Lasch-Collins had... much larger numbers than Cortez did. So even the standstill is an impressive military achievement, especially because he's fighting without native support. So what are the numbers even at this point? A Speaker 2 (6:02) few hundred on Cortez's side and multiple thousands on the Lashkaran's side. It's at this point that the critical technological differentials in the old and new world really begin to come into effect. The classic text which got me invested in this whole scenario in the first place is Jared Diamond's book, Guns, Germs, and Steel. He enumerates in the title those critical advantages that the Spaniards had. Guns, in reality, weren't so significant. Once the native peoples got over the shock value, they appreciated, given the very slow reloading times involved in firearms at that time, that they weren't so significant as assets on the battlefield. But steel was critical. Local weapons were carved from wood and from stone and from obsidian, that volcanic glass, which is... razor sharp when honed to a point and quite dangerous as a slashing weapon. But against the steel armor and especially the steel helmets that the conquistadors were wearing, it was much less effective. And the conquistadors were drawing on military traditions of the old world that went back, incorporating long Toledo steel sword blades. They used those as thrusting weapons to take out indigenous warriors who were coming in with cut and slash weapons, which of course open up the side of the body to be taken out very early. So the combination of the technology with generations of inherited military training and skill meant that the conquistadors had that critical edge on the battlefield. Now they weren't invincible, and Cortes again playing those mind games. He was taking casualties, and he was careful to bury his dead underneath the houses that they were sheltering in, so the Luskallans wouldn't be aware that they were even having some successes in hand-to-hand combat. It was as much a mind game as it was a physical game. And the ultimate weapon, of course, the conquistadors brought with them was their horses. I cannot emphasize or overemphasize enough how vital the horse was to the conquistadors once they entered into the interior of the American continents. They had the external asset. They had sail power, which enabled them to land anywhere they wanted on the coast. But in the interior, the horse was decisive. There were no native equivalents. The horse originated in North America, but it had subsequently died out. And the local peoples had not just no horses, but no beast of burden generally. That was not integrated into their economies, into their ways of life, or into their military. The Inca, who we'll discuss in a moment, they did have one, which was the llama. And when they campaigned, their armies trailing for miles behind them would be these endless baggage trains of pack animals, llamas. The Aztecs had no equivalent. Their only domestic animals were the turkey and the chihuahua. And speaking of dogs, the conquistadors also bought these big war mastiffs, these fighting dogs which wore armor and were trained to take down men. Again, imagine the terrifying impact that would have for the indigenous people. But the horse was the critical asset. On attack, you could blast through any native formation, which didn't not just have the weapons, but the training or discipline to be able to stand up to mass-shocked cavalry. And if things were going bad for the conquistadors, they could retreat much faster. then of course the enemies could chase them. So the Lashkalans appreciate all these assets coming together and they see this as their opportunity. They were the holdouts, the last remaining major entity in Mesoamerica, which was still able to go toe to toe with the Aztecs. They've been completely surrounded. The Aztecs were upping the ante every year with these ceremonial flower wars, which are becoming more and more obviously wars of conquest. And the Lashkalans have been cut off from the coast and from sources of salt, right? So they were being pushed to the brink. This is a Hail Mary for them. If we ally with these outsiders, these strangers, who are just few in number after all, we may have some potential way to break out of this strategic trap that we've had imposed upon us. So they lean over to the sides of Cortes and they travel with him to Tenochtitlan, the capital, the glittering jewel in the midst of Lake Texcoco, the capital of the Aztec Empire. And again, this is a dramatic moment when Cortes... passes through the causeways out into the city and encounters Moctezuma II, the Huey-Latawane, as he was called, the great speaker, the emperor of the Aztec Empire. And these two worlds come together at that moment. The interface between them was Cortes' interpreter slash mistress, Donna Marina Malinche, as she became known, who is translating from one side to the other. So the dialogue that occurs then is one of those great tipping points in history. What was the perspective of Moctezuma II? He was aware Cortes was coming. This is his empire. He has envoys and emissaries and scouts and spies everywhere. And they're reporting back to him that something has washed up on the shores of our empire and it is determined to meet with us. He initially bargains with Cortes, urging him to leave. He provides him with precious gifts, which of course just inflames Cortes even more. And just once he's got hold of Aztec gold, he's just determined to go all the way to the center. So he continues playing this double game. His advisors, his counsel. urged him not to allow Cortes to proceed to the capital. His own brother, Cuitlahuaq, tells him, if you allow this man inside your house, he will take your house away from you. But Moctezuma proceeds. And from that, he's been condemned by generations of historians. This was a mistake to bring the conquistadors into the heart of the empire itself. I actually think that was his best option, whether he was aware of it or not, because it was better for him to have Cortes as his guest within Tenochtitlan than it was to have Cortes this random element at loose within his empire, talking to the subject peoples, inflaming them possibly against central authority. He felt perhaps Cortes was what he said he was, an envoy from a great emperor on the far side of the vast ocean. Cortes, again with the mind games, had no warrant to say he was a diplomat or ambassador for anybody. He kept telling anyone who'd listen, I speak for the mighty Charles V, the Holy Roman Emperor. Of course, Charles V had no idea who Hernan Cortes was. Cortes, again, is just winging it. The incredible improvisation here. And for a moment, the stasis. The great turning point comes when word arrives from the coast that one of the Aztec regional military officers, on his own initiative, has taken action against the conquistadors left behind on the coast, the ones with the Totonacs, and some of them have been killed. Speaker 2 (12:16) Cortes sees this as his pretext. He marches into the palace of Moctezuma II, the Aztec, Huey Latoani, tells him that for his own safety, he was now being taken under the protective custody of the Spanish, and he should come with him or else there will be violence. And this is the moment when Moctezuma's entire worldview just collapses, right? Nobody had spoken to him like this before. His psychology just disintegrates at that point, and he meekly allows himself to be led away. He tells his people, don't resist. I don't want bloodshed. I will pass with these strangers. And then once Cortes is rounded up, the officers at the coast responsible for turning on his men there, he has them in front of the emperor and the entire court burned alive, which is a form of punishment totally unknown to the Aztecs. And they watch this in grim silence. So once Cortes has seized the emperor himself, once he has Moctezuma, he already has the empire. He governs through what is increasingly becoming... his puppet. And Moctezuma seems to have fallen almost under the spell of Cortes, the classic Stockholm syndrome. He gives him a grand tour of the city. Cortes, and again, a subtle flex on his power, has brigantines, small sailing boats built, and he takes Moctezuma with him on a sailing cruise on Lake Tishcoco. And the emperor is astonished at this new technology of using the wind to sail on the water. Having the emperor was the key. So the emperor's mistake wasn't inviting Cortes into the city. It was making himself vulnerable by staying there also in an adjacent palace. If he had gone to some further location, made some excuse, a pilgrimage or an expedition of some kind, and had ruled through subordinates, Cortes would have been baffled. He couldn't go chasing after the emperor. That would be obviously too provocative. But without the emperor there, Cortes would have had his options extremely limited. And I don't know what he would have done in that circumstance. Because Moctezuma stayed in his capital, he made himself the target. Once he was taken, this was the key to controlling the entire empire at that point. Speaker 1 (14:15) So obviously the story continues from there. La noche triste. What people might not appreciate about what happened here, in both the Pizarro story of the Inca empire, which we'll talk about later, and in the Aztec story, is that in both cases, the Spanish were themselves divided and in fact fighting each other. Speaker 1 (14:37) Maybe you should tell the story how Velazquez sends another expedition to go capture and arrest Cortes for going beyond the prerogative of his mission. Speaker 2 (14:48) Absolutely. We left the governor on Cuba, of course, fuming. He rallies another expeditionary force because Cortes is stealing his thunder. And he sends us under Penfeo de Nevaez, a larger force than the one Cortes brought with him originally. This lands on the coast. Cortes appreciates he has to move, so he leaves one of his subordinates, the hot-blooded Alvarado, behind in charge in Tenochtitlan, takes as many men as he can to the coast, confronts. De Nevaez defeats him in a minor battle. And again, the diplomacy wins over the entire expeditionary force that the governor had dispatched. He tells them, my friends, why are we fighting? We have the empire at my disposal. Join with me and we can share in the riches. So he wins over the vast majority of this new force. It becomes effectively reinforcement. marches back to the capital. He finds the Mutas turned against him. The problem with not being in charge is you can't be everywhere. And his subordinate, assuming that the Aztecs were mobilizing against him, has had a preemptive strike. There was a festival. The aristocracy, particularly the warrior caste, were celebrating. And Alvarado just descended on them, massacred everybody. The survivors rally the population. And when Cortes returns, he finds himself effectively under siege. The people are so appalled now with the failure of their Huey Letoani. When he tries to pacify them, they throw stones at him. Mortally wounded, he either dies or the Spanish finish him off because he's no longer any use to them. So now Cortes is trapped in the city, in Tenochtitlan. He determines to break out. And that is, as you say, La Noche Triste, the tragic night, because so many of his men are left behind. They're either killed as they try to escape the city across the causeways or forced to retreat back to the palaces and they're taken alive and sacrificed subsequently. Cortes gets away with a minority of the troops still at his disposal and makes it back to Lashkarlan territory. That was the critical aspect, the two features of the entire campaign. One, he has enough strike power with enough horses to defeat the Aztecs when they try to finish him off at the Battle of Otumbo. They feel he's on the run. They have the numbers, the conquistadors dragging their tails between their legs as they flee. Cortes himself is grievously wounded. We can finish them off. Speaker 1 (16:59) And Speaker 2 (16:59) they had the numbers, they were winning, but again, Cortes identifies where the Aztec general is. He rallies enough horsemen to blast through the Aztec ranks and take out their command and control. The Aztec army disintegrates and the Spanish are able to flee. So the battlefield of bondages, they had their horses, their steel, critical, but just as critical was the diplomacy. If the Lashkarans had turned on Cortes at that point, he would have been finished. Not one Spaniard would have survived. None of them would have made it back to the coast. But the Lashkarans see for their own reasons, not out of any generosity or humanitarian impulse to welcome back the conquistadors, they still see we are committed to these people and to our alliance. So they give Cortes shelter. He recovers physically, begins to rebuild his strength, and is determined to go back to Tenochtitlan. And for round two, and this time, we're not going to be... indulging diplomatic niceties. The Lashkalans, their own perspective on this, if you go to Lashkala territory today, the governor's mansion there has murals on the wall. And these depict the Cortes and the conquistadors from the Lashkalan point of view. And it's fascinating to look at how the relationship is not between a superior and a inferior. It's between equals. You see them depicted in the same scale, engaged in diplomacy between partners, not between subordinates and dominant figures. The Lashkalans... drove a hard bargain. We want territory carved out of the Aztecs. We want our own fortress in Tenochtitlan after this is over. They saw this as them using the conquistadors, not the other way around, which is very important to bear in mind. That the Aztec empire from a distance, if you look at a map, seemed impressive. But this was an imperial construct and not just the remaining independent entities like the Lashkalans, like the Tarascans, who we can discuss later. were hostile to the Aztecs, so were so many of their subordinated peoples. The Totonacs on the coast, the Chalco states on the shores of Lake Texcoco, they chafed under Aztec hegemony and authority. And they too saw the conquistadors as an opportunity to finally shrug off the authority, the demands of the Aztecs and get revenge in a lot of ways. So as Cortes builds up for the final campaign against Tenochtitlan against the new Huey-Latawane, Cuitlahuec. And then after he died, his brother, the last of the Huey-Latawanese, called Tomac, he has indigenous people flocking to his banner from all over Mesoamerica. He's emphasized that he's still in the fight. He still has those advantages. More reinforcements are arriving at the coast and they're being integrated into the conquistador army. But the force that marches on Tenochtitlan, the total numbers, the conquistadors were maybe one half of 1 % in raw numbers of that force. The overwhelming majority were other Mesoamerican peoples who see this as their final reckoning with the Aztecs. And this is the integration again of the technology with the diplomacy. Cortes knows to take the city, he has to control the lake. And again, the innovations, they need sulfur for their gunpowder. They have guns useless without gunpowder. So an expedition goes into the mountains to the volcano, Popacatapetl. and they dangle with ropes inside the caldera of the volcano, scooping out the sulfur they need as the critical ingredient for their gunpowder. Another one. builds prefabricated brigantines boats in their different sections and then has untold numbers of porters, human load-bearers, bring these prefabricated pieces over the mountains to the lake. They're assembled and then they loosen the lake and then now they have control over the lake. So bringing together the technology, the innovations with the local manpower and this is the force directed against Tenochtitlan in the final battle. Speaker 1 (20:45) I actually didn't know those stories. That's crazy. One of the ways in which, to the extent people are even aware of the story, they might not understand what actually happened is they have this model of the Aztecs or the Incas as this cohesive single nation. And I think a better model might be something like, imagine if it's Russia and Ukraine have been doing trench warfare for 100 years. And imagine the animosity. And then also the Russians are like taking tens of thousands of Ukrainians and like doing human sacrifices with them. and then if some foreign force comes in and says to the Ukrainians, we can help you march into Moscow, I think they'd have a pretty decent odds of getting some agreement there. Speaker 2 (21:27) Absolutely. The old phrase is the enemy of my enemy is my friend and diplomacy war, that's always very good. Speaker 1 (21:33) I don't think I actually appreciated the ambition of Jane Street's intern projects until last week when I got to see some of them for myself. For example, one intern spent part of his summer researching LLM memorization. figuring out how to quantify and reduce it without hurting out-of-sample performance. This matters because whenever Jane Street evaluates a new model on historical data, they need to know that its performance reflects predictive power, not just memorization of past outcomes. Another intern built a custom activation checkpointing scheme. Activation checkpointing lets you trade compute for memory. You recalculate some activations during backprop instead of storing them all after the forward pass. This intern found a way to identify the activations that are cheapest to recompute but that still free up a lot of memory. And this allowed his version to outperform PyTorch's native one. These are just two examples, but Jane Street has written about a bunch more. These write-ups are coming out in batches. The first few are live now, including these two, and the rest will be published in the coming weeks. If you want to read them, Or if you want to apply for Jane Street's 2027 summer internships, go to janestreet.com slash thorkesh. There's so many interesting questions to ask from everything from technology to diplomacy to disease to tactics. Before you get to that, I think just to round out the story, in many ways, what's striking about the... conquest of the Incas in Peru under Pizarro ten years later is how similar it was to Cortez's story how much he just basically followed the playbook. But I want to just people to have a sense of roughly what happened here. Starting I think maybe with a battle of Cajamarca might be the most astonishing military lopsided encounter that has maybe ever happened in human history. So I would Yeah, if you can recapitulate a bit of the, at least that battle, and then just the overall story, and then we can do some analysis from there. Speaker 2 (23:26) Absolutely. When Cortes consummates his conquest of Tenerife in 1521, the last of the Huey Latamani surrenders to him and now he occupies the territory, and most importantly, the top of the social hierarchy. The existing structure, as much as possible, is allowed to persist. The conquistadors just decapitate the local nobility and insert themselves at the top. Now, this is the playbook that will continue to be applied less successfully throughout the rest of Mesoamerica because the existing political entities there aren't so sophisticated. Nonetheless, there are rumors. There are always rumors of lost cities of gold and more conquistadors are now flooding into the new world to seek advantage of this. One of this is a distant cousin of Cortes named Francisco Pizarro. He met with Cortes and got the playbook, as you say, about how this is to be done. And then... Again, in one of these conquistador business ventures, he finds the funding for men and ships and begins pushing south down the west coast of South America, crossing the equator and finally