Very interesting post! However, I have a big disagreement with your interpretation of why the European conquerors succeeded in America, and I think that it undermines much of your conclusion.

In your section titled "What explains these devastating takeovers?" you cite technology and strategic ability, but Old World diseases destroyed the communities in America before the European invaders arrived, most notably smallpox, but also measles, influenza, typhus and the bubonic plague. My reading of historians (from Charles Mann's book 1493, to Alfred W. Crosby's The Columbian Exchange and Jared Diamond's Guns Germs and Steel) leads me to conclude that the historical consensus is that the reason for all of these takeovers was due to Old World diseases, and had relatively little to do with technology or strategy per se.

In Chapter 11 of Guns Germs and Steel, Jared Diamond analyzes the European takeovers in America you cite from the perspective of old World diseases (Here's a video from a Youtuber named CGP Grey who made a video on the same topic). The basic thesis is that Europeans had acquired immunity from these diseases, whereas people in America hadn't. From Wikipedia,

After first contacts with Europeans and Africans, some believe that the death of 90–95% of the native population of the New World was caused by Old World diseases.[43] It is suspected that smallpox was the chief culprit and responsible for killing nearly all of the native inhabitants of the Americas.

These diseases were endemic by the time that Cortes and Pizarro arrived on the continent, and therefore it seems very unlikely that their victory was achieved primarily from military and technological might. From Wikipedia again,

The Spanish Franciscan Motolinia left this description: "As the Indians did not know the remedy of the disease…they died in heaps, like bedbugs. In many places it happened that everyone in a house died and, as it was impossible to bury the great number of dead, they pulled down the houses over them so that their homes become their tombs."[46] On Cortés's return, he found the Aztec army’s chain of command in ruins. The soldiers who still lived were weak from the disease. Cortés then easily defeated the Aztecs and entered Tenochtitlán.[47] The Spaniards said that they could not walk through the streets without stepping on the bodies of smallpox victims
The effects of smallpox on Tahuantinsuyu (or the Inca empire) were even more devastating. Beginning in Colombia, smallpox spread rapidly before the Spanish invaders first arrived in the empire. The spread was probably aided by the efficient Inca road system. Within months, the disease had killed the Incan Emperor Huayna Capac, his successor, and most of the other leaders. Two of his surviving sons warred for power and, after a bloody and costly war, Atahualpa become the new emperor. As Atahualpa was returning to the capital Cuzco, Francisco Pizarro arrived and through a series of deceits captured the young leader and his best general. Within a few years smallpox claimed between 60% and 90% of the Inca population,[49] with other waves of European disease weakening them further.

The theory that disease was more important than technology is further supported empirically by the fact that Europeans were unable to conquer African tribes/civilizations until the late 19th century, long after the conquest of the New World, despite the fact that many African civilizations had similar or even lower technological capabilities compared to the Inca and Aztecs. The reason is because Africans had immunity to Old World diseases, unlike Americans. However, even in the 19th century conquests, historians often cite the development of the drug quinine, and thus immunity to disease, as one of the primary reasons why European civilizations were able to conquer African nations.

By contrast, I was only able to find one mention of smallpox in your entire post, and the place where you do mention it, you say

Smallpox sweeps through the land, killing many on all sides and causing general chaos.

If I'm reading "all sides" correctly, this is just flat-out incorrect. It killed mainly Americans.

At one point you state that during Pizarro's conquest,

The Inca empire is in the middle of a civil war and a devastating plague.

This "plague" was smallpox carried from earlier European travelers. Jared Diamond says

The reason for the civil war was that an epidemic of smallpox, spreading overland among South American Indians after its arrival with Spanish settlers in Panama and Colombia, had killed the Inca emperor Huayna Capac and most of his court around 1526, and then immediately killed his designated heir, Ninan Cuyuchi.

You may ask why there was an asymmetry: after all, didn't the New World have diseases that Europeans were not immune to? Yes, but basically only syphilis. Europeans had exposure to many infectious diseases because those diseases had been acquired from livestock, but livestock was not an important component of American civilizations in the pre-Columbian period.

One reason why disease might not be salient in descriptions of the American conquest is because until modern times, historians emphasized explanations of events in terms of human-factors, such as personalities of rulers and tendencies of groups of people. According to this source, it wasn't until the 1960s that historians started to take seriously the idea that disease was the primary culprit in the destruction of American civilizations.

There still could be an analogous situation where AI develops diseases that kills humans but not AI, but I think it's worth exploring this type of existential risk in its own category, and emphasize that this thesis does not depend on a historical precedent of conquerors having strategic or technological advantages.

Showing 3 of 12 replies (Click to show all)

Update: I do think it would be good to look at the Black Death in Europe and see whether there were similar political "upsets" where a small group of outsiders took over a large region in the turmoil. I predict that there mostly weren't; if it turns out this did happen a fair amount, then I agree that is good evidence that disease was really important.

4Matthew Barnett3moFor my part, I think you summarized my position fairly well. However, after thinking about this argument for another few days, I have more points to add. * Disease seems especially likely to cause coordination failures since it's an internal threat rather than an external threat (which unlike internal threats, tend to unite empires). We can compare the effects of the smallpox epidemic in the Aztec and Inca empires alongside other historical diseases during wartime, such as the Plauge of Athens [] which arguably is what caused Athens to lose the Peloponnesian War. * Along these same lines, the Aztec/Inca didn't have any germ theory of disease, and therefore didn't understand what was going on. They may have thought that the gods were punishing them for some reason, and therefore they probably spent a lot of time blaming random groups for the catastrophe. We can contrast these circumstances to eg. the Paraguayan War [] which killed up to 90% of the male population, but people probably had a much better idea what was going on and who was to blame, so I expect that the surviving population had an easier time coordinating. * A large chunk of the remaining population likely had some sort of disability. Think of what would happen if you got measles and smallpox in the same two year window: even if you survived it probably wouldn't look good. This means that the pure death rate is an underestimate of the impact of a disease. The Aztecs, for whom "only" 40 percent died of disease, were still greatly affected []
2Daniel Kokotajlo3moI accept that these points are evidence in your favor. Here are some more of my own: --Smallpox didn't hit the Aztecs until Cortes had already killed the Emperor and allied with the Tlaxcalans, if I'm reading these summaries correctly. (I really should go read the actual books...) So it seems that Cortes did get really far on the path towards victory without the help of disease. More importantly, there doesn't seem to be any important difference in how people treated Cortes before or after the disease. They took him very seriously, underestimated him, put too much trust in him, allied with him, etc. before the disease was a factor. --When Pizarro arrived in Inca lands, the disease had already swept through, if I'm reading these stories right. So the period of most chaos and uncertainty was over; people were rebuilding and re-organizing. --Also, it wasn't actually a 90% reduction in population. It was more like a 50% reduction at the time, if I am remembering right. (Later epidemics would cause further damage, so collectively they were worse than any other plague in history.) This is comparable to e.g. the Black Death in Europe, no? But the Black Death didn't result in the collapse of most civilizations who went through it, nor did it result in random small groups of adventurers taking over governments, I predict. (I haven't actually read up on the history of it)

Cortés, Pizarro, and Afonso as Precedents for Takeover

by Daniel Kokotajlo 10 min read1st Mar 202032 comments


Crossposted from AI Impacts.

Epistemic status: I am not a historian, nor have I investigated these case studies in detail. I admit I am still uncertain about how the conquistadors were able to colonize so much of the world so quickly. I think my ignorance is excusable because this is just a blog post; I welcome corrections from people who know more. If it generates sufficient interest I might do a deeper investigation. Even if I’m right, this is just one set of historical case-studies; it doesn’t prove anything about AI, even if it is suggestive. Finally, in describing these conquistadors as “successful,” I simply mean that they achieved their goals, not that what they achieved was good.


In the span of a few years, some minor European explorers (later known as the conquistadors) encountered, conquered, and enslaved several huge regions of the world. That they were able to do this is surprising; their technological advantage was not huge. (This was before the scientific and industrial revolutions.) From these cases, I think we learn that it is occasionally possible for a small force to quickly conquer large parts of the world, despite:

  1. Having only a minuscule fraction of the world's resources and power
  2. Having technology + diplomatic and strategic cunning that is better but not that much better
  3. Having very little data about the world when the conquest begins
  4. Being disunited

Which all suggests that it isn’t as implausible that a small AI takes over the world in mildly favorable circumstances as is sometimes thought.

EDIT: In light of good pushback from people (e.g. Lucy.ea8 and e.g. Matthew Barnett) about the importance of disease, I think one should probably add a caveat to the above: "In times of chaos & disruption, at least."

Three shocking true stories

I highly recommend you read the wiki pages yourself; otherwise, here are my summaries:

Cortés: [wiki] [wiki]

  • April 1519: Hernán Cortés lands in Yucatan with ~500 men, 13 horses, and a few cannons. He destroys his ships so his men won't be able to retreat. His goal is to conquer the Aztec empire of several million people.
  • He makes his way towards the imperial capital, Tenochtitlán. Along the way he encounters various local groups, fighting some and allying with some. He is constantly outnumbered but his technology gives him an advantage in fights. His force grows in size, because even though he loses Spaniards he gains local allies who resent Aztec rule.
  • Tenochtitlán is an island fortress (like Venice) with a population of over 200,000, making it one of the largest and richest cities in the world at the time. Cortés arrives in the city asking for an audience with the Emperor, who receives him warily.
  • Cortés takes the emperor hostage within his own palace, indirectly ruling Tenochtitlán through him.
  • Cortés learns that the Spanish governor has landed in Mexico with a force twice his size, intent on arresting him. (Cortés' expedition was illegal!) Cortés leaves 200 men guarding the Emperor, marches to the coast with the rest, surprises and defeats the new Spaniards in battle, and incorporates the survivors into his army.
  • July 1520: Back at the capital, the locals are starting to rebel against his men. Cortés marches back to the capital, uniting his forces just in time to be besieged in the imperial palace. They murder the emperor and fight their way out of the city overnight, taking heavy losses.
  • They shelter in another city (Tlaxcala) that was thinking about rebelling against the Aztecs. Cortés allies with the Tlaxcalans and launches a general uprising against the Aztecs. Not everyone sides with him; many city-states remain loyal to Tenochtitlan. Some try to stay neutral. Some join him at first, and then abandon him later. Smallpox sweeps through the land, killing many on all sides and causing general chaos.
  • May 1521: The final assault on Tenochtitlán. By this point, Cortés has about 1,000 Spanish troops and 80,000 - 200,000 allied native warriors. He had 16 cannons and 13 boats. The Aztecs have 80,000 - 300,000 warriors and 400 boats. Cortés and his allies win.
  • Later, the Spanish would betray their native allies and assert hegemony over the entire region, in violation of the treaties they had signed.

Pizarro [wiki] [wiki]

  • 1532: Francisco Pizarro arrives in Inca territory with 168 Spanish soldiers. His goal is to conquer the Inca empire, which was much bigger than the Aztec empire.
  • The Inca empire is in the middle of a civil war and a devastating plague.
  • Pizarro makes it to the Emperor right after the Emperor defeats his brother. Pizarro is allowed to approach because he promises that he comes in peace and will be able to provide useful information and gifts.
  • At the meeting, Pizarro ambushes the Emperor, killing his retinue with a volley of gunfire and taking him hostage. The remainder of the Emperor's forces in the area back away, probably confused and scared by the novel weapons and hesitant to keep fighting for fear of risking the Emperor's life.
  • Over the next months, Pizarro is able to leverage his control over the Emperor to stay alive and order the Incans around; eventually he murders the Emperor and makes an alliance with local forces (some of the Inca generals) to take over the capital city of Cuzco.
  • The Spanish continue to rule via puppets, primarily Manco Inca, who is their puppet ruler while they crush various rebellions and consolidate their control over the empire. Manco Inca escapes and launches a rebellion of his own, which is partly successful: He utterly wipes out four columns of Spanish reinforcements, but is unable to retake the capital. With the morale and loyalty of his followers dwindling, Manco Inca eventually gives up and retreats, leaving the Spanish still in control.
  • Then the Spanish ended up fighting each other for a while, while also putting down more local rebellions. After a few decades Spanish dominance of the region is complete. (1572).

Afonso [wiki] [wiki] [wiki]

  • 1506: Afonso helps the Portuguese king come up with a shockingly ambitious plan. Eight years prior, the first Europeans had rounded the coast of Africa and made it to the Indian Ocean. The Indian Ocean contained most of the world's trade at the time, since it linked up the world's biggest and wealthiest regions. See this map of world population (timestamp 3:45). Remember, this is prior to the Industrial and Scientific Revolutions; Europe is just coming out of the Middle Ages and does not have an obvious technological advantage over India or China or the Middle East, and has an obvious economic disadvantage. And Portugal is a just tiny state on the edge of the Iberian peninsula.
  • The plan is: Not only will we go into the Indian Ocean and participate in the trading there -- cutting out all the middlemen who are currently involved in the trade between that region and Europe -- we will conquer strategic ports around the region so that no one else can trade there!
  • Long story short, Afonso goes on to complete this plan by 1513. (!!!)

Some comparisons and contrasts:

  • Afonso had more European soldiers at his disposal than Cortes or Pizarro, but not many more -- usually he had about a thousand or so. He did have more reinforcements and support from home.
  • Like them, he was usually significantly outnumbered in battles. Like them, the empires he warred against were vastly wealthier and more populous than his forces.
  • Like them, Afonso was often able to exploit local conflicts to gain local allies, which were crucial to his success.
  • Unlike them, his goal wasn't to conquer the empires entirely, just to get and hold strategic ports.
  • Unlike them, he was fighting empires that were technologically advanced; for example, in several battles his enemies had more cannons and gunpowder than he did.
  • That said, it does seem that Portuguese technology was qualitatively better in some respects (ships, armor, and cannons, I'd say.) Not dramatically better, though.
  • While Afonso's was a naval campaign, he did fight many land battles, usually marine assaults on port cities, or defenses of said cities against counterattacks. So superior European naval technology is not by itself enough to explain his victory, though it certainly was important.
  • Plague and civil war were not involved in Afonso's success.

What explains these devastating conquests?

Wrong answer: I cherry-picked my case studies.

History is full of incredibly successful conquerors: Alexander the Great, Ghenghis Khan, etc. Perhaps some people are just really good at it, or really lucky, or both.

However: Three incredibly successful conquerors from the same tiny region and time period, conquering three separate empires? Followed up by dozens of less successful but still very successful conquerors from the same region and time period? Surely this is not a coincidence. Moreover, it’s not like the conquistadors had many failed attempts and a few successes. The Aztec and Inca empires were the two biggest empires in the Americas, and there weren’t any other Indian Oceans for the Portuguese to fail at conquering.

Fun fact: I had not heard of Afonso before I started writing this post this morning. Following the Rule of Three, I needed a third example and I predicted on the basis of Cortes and Pizarro that there would be other, similar stories happening in the world at around that time. That’s how I found Afonso.

Right answer: Technology

However, I don't think this is the whole explanation. The technological advantage of the conquistadors was not overwhelming.

Whatever technological advantage the conquistadors had over the existing empires, it was the sort of technological advantage that one could acquire before the Scientific and Industrial revolutions. Technology didn't change very fast back then, yet Portugal managed to get a lead over the Ottomans, Egyptians, Mughals, etc. that was sufficient to bring them victory. On paper, the Aztecs and Spanish were pretty similar: Both were medieval, feudal civilizations. I don't know for sure, but I'd bet there were at least a few techniques and technologies the Aztecs had that the Spanish didn't. And of course the technological similarities between the Portuguese and their enemies were much stronger; the Ottomans even had access to European mercenaries! Even in cases in which the conquistadors had technology that was completely novel -- like steel armor, horses, and gunpowder were to the Aztecs and Incas -- it wasn't god-like. The armored soldiers were still killable; the gunpowder was more effective than arrows but limited in supply, etc.

(Contrary to popular legend, neither Cortés nor Pizarro were regarded as gods by the people they conquered. The Incas concluded pretty early on that the Spanish were mere men, and while the idea did float around the Aztecs for a bit the modern historical consensus is that most of them didn't take it seriously.)

Ask yourself: Suppose Cortés had found 500 local warriors, gave them all his equipment, trained them to use it expertly, and left. Would those local men have taken over all of Mexico? I doubt it. And this is despite the fact that they would have had much better local knowledge than Cortés did! Same goes for Pizarro and Afonso. Perhaps if he had found 500 local warriors led by an exceptional commander it would work. But the explanation for the conquistador’s success can’t just be that they were all exceptional commanders; that would be positing too much innate talent to occur in one small region of the globe at one time.

Right answer: Strategic and diplomatic cunning

This is my non-expert guess about the missing factor that joins with technology to explain this pattern of conquistador success.

They didn't just have technology; they had effective strategy and they had effective diplomacy. They made long-term plans that worked despite being breathtakingly ambitious. (And their short-term plans were usually pretty effective too, read the stories in detail to see this.) Despite not knowing the local culture or history, these conquistadors made surprisingly savvy diplomatic decisions. They knew when they could get away with breaking their word and when they couldn't; they knew which outrages the locals would tolerate and which they wouldn’t; they knew how to convince locals to ally with them; they knew how to use words to escape militarily impossible situations… The locals, by contrast, often badly misjudged the conquistadors, e.g. not thinking Pizarro had the will (or the ability?) to kidnap the emperor, and thinking the emperor would be safe as long as they played along.

This raises the question, how did they get that advantage? My answer: they had experience with this sort of thing, whereas locals didn't. Presumably Pizarro learned from Cortés' experience; his strategy was pretty similar. (See also: the prior conquest of the Canary Islands by the Spanish). In Afonso's case, well, the Portuguese had been sailing around Africa, conquering ports and building forts for more than a hundred years.

Lessons I think we learn

I think we learn that:

It is occasionally possible for a small force to quickly conquer large parts of the world, despite:

  1. Having only a minuscule fraction of the world's resources and power
  2. Having technology + diplomatic and strategic cunning that is better but not that much better
  3. Having very little data about the world when the conquest begins
  4. Being disunited

Which all suggests that it isn’t as implausible that a small AI takes over the world in mildly favorable circumstances as is sometimes thought.

EDIT: In light of good pushback from people (e.g. Lucy.ea8 and e.g. Matthew Barnett) about the importance of disease, I think one should probably add a caveat to the above: "In times of chaos & disruption, at least."

Having only a minuscule fraction of the world's resources and power

In all three examples, the conquest was more or less completed without support from home; while Spain/Portugal did send reinforcements, it wasn't even close to the entire nation of Spain/Portugal fighting the war. So these conquests are examples of non-state entities conquering states, so to speak. (That said, their claim to represent a large state may have been crucial for Cortes and Pizarro getting audiences and respect initially.) Cortés landed with about a thousandth the troops of Tenochtitlan, which controlled a still larger empire of vassal states. Of course, his troops were better equipped, but on the other hand they were also cut off from resupply, whereas the Aztecs were in their home territory, able to draw on a large civilian population for new recruits and resupply.

The conquests succeeded in large part due to diplomacy. This has implications for AI takeover scenarios; rather than imagining a conflict of humans vs. robots, we could imagine humans vs. humans-with-AI-advisers, with the latter faction winning and somehow by the end of the conflict the AI advisers have managed to become de facto rulers, using the humans who obey them to put down rebellions by the humans who don't.

Having technology + diplomatic and strategic skill that is better but not that much better

As previously mentioned, the conquistadors didn’t enjoy god-like technological superiority. In the case of Afonso the technology was pretty similar. Technology played an important role in their success, but it wasn’t enough on its own. Meanwhile, the conquistadors may have had more diplomatic and strategic cunning (or experience) than the enemies they conquered. But not that much more--they are only human, after all. And their enemies were pretty smart.

In the AI context, we don't need to imagine god-like technology (e.g. swarms of self-replicating nanobots) to get an AI takeover. It might even be possible without any new physical technologies at all! Just superior software, e.g. piloting software for military drones, targeting software for anti-missile defenses, cyberwarfare capabilities, data analysis for military intelligence, and of course excellent propaganda and persuasion.

Nor do we need to imagine an AI so savvy and persuasive that it can persuade anyone of anything. We just need to imagine it about as cunning and experienced relative to its enemies as Cortés, Pizarro, and Afonso were relative to theirs. (Presumably no AI would be experienced with world takeover, but perhaps an intelligence advantage would give it the same benefits as an experience advantage.) And if I’m wrong about this explanation for the conquistador’s success--if they had no such advantage in cunning/experience--then the conclusion is even stronger.

Additionally, in a rapidly-changing world that is undergoing slow takeoff, where there are lesser AIs and AI-created technologies all over the place, most of which are successfully controlled by humans, AI takeover might still happen if one AI is better, but not that much better, than the others.

Having very little data about the world when the conquest begins

Cortés invaded Mexico knowing very little about it. After all, the Spanish had only realized the Americas existed two decades prior. He heard rumors of a big wealthy empire and he set out to conquer it, knowing little of the technology and tactics he would face. Two years later, he ruled the place.

Pizarro and Afonzo were in better epistemic positions, but still, they had to learn a lot of important details (like what the local power centers, norms, and conflicts were, and exactly what technology the locals had) on the fly. But they were good at learning these things and making it up as they went along, apparently.

We can expect superhuman AI to be good at learning. Even if it starts off knowing very little about the world -- say, it figured out it was in a training environment and hacked its way out, having inferred a few general facts about its creators but not much else -- if it is good at learning and reasoning, it might still be pretty dangerous.

Being disunited

Cortés invaded Mexico in defiance of his superiors and had to defeat the army they sent to arrest him. Pizarro ended up fighting a civil war against his fellow conquistadors in the middle of his conquest of Peru. Afonzo fought Greek mercenaries and some traitor Portuguese, conquered Malacca against the orders of a rival conquistador in the area, and was ultimately demoted due to political maneuvers by rivals back home.

This astonishes me. Somehow these conquests were completed by people who were at the same time busy infighting and backstabbing each other!

Why was it that the conquistadors were able to split the locals into factions, ally with some to defeat the others, and end up on top? Why didn't it happen the other way around: some ambitious local ruler talks to the conquistadors, exploits their internal divisions, allies with some to defeat the others, and ends up on top?

I think the answer is partly the "diplomatic and strategic cunning” mentioned earlier, but mostly other things. (The conquistadors were disunited, but presumably were united in the ways that mattered.) At any rate, I expect AIs to be pretty good at coordinating too; they should be able to conquer the world just fine even while competing fiercely with each other. For more on this idea, see this comment.

By Daniel Kokotajlo


Thanks to Katja Grace for feedback on a draft. All mistakes are my own, and should be pointed out in the comments. Edit: Also, when I wrote this post I had forgotten that the basic idea for it probably came from this comment by JoshuaFox.