What do you think?
Rate this book
The Killing Age: How Violence Made the Modern World
A bracing account of how our current planetary crisis emerged from the worst cataclysmic destruction in human history, which Clifton Crais terms the Mortecene—the killing age.
We are used to speaking of the Anthropocene and the outsized impact humans have had on the planet. But we sometimes lose sight of a fundamental truth at the heart of modern world history—the legacy of human predation, slavery, and imperialism that has devastated the natural world and led us to our present moment. As historian Clifton Crais shows in this magisterial work, the period that we most associate with human progress—which gave us the Enlightenment, the birth of democracies, the Industrial Revolution, and more—was at the same time catastrophically destructive.
In this bracing, landmark book, Crais urges us to view the growth of global capitalism between 1750 and the early 1900s not as the Anthropocene, but the the Killing Age. Killing brought the world together and tore it apart, as profiteering warlords committed mass-scale slaughter of humans and animals across Africa, Asia, and the Americas. The newfound ease and profitability of killing created a disturbing network of global connections and economies, eliminating tens of millions of people and sparking an environmental crisis that remains the most urgent catastrophe facing the world today.
Drawing on years of scholarship and marshaling myriad sources across world history, The Killing Age turns our vision of past and present on its head, illuminating the Mortecene in all its horror—how it shaped who we are, what we value and fear, and the precarious present we inhabit today.
We are used to speaking of the Anthropocene and the outsized impact humans have had on the planet. But we sometimes lose sight of a fundamental truth at the heart of modern world history—the legacy of human predation, slavery, and imperialism that has devastated the natural world and led us to our present moment. As historian Clifton Crais shows in this magisterial work, the period that we most associate with human progress—which gave us the Enlightenment, the birth of democracies, the Industrial Revolution, and more—was at the same time catastrophically destructive.
In this bracing, landmark book, Crais urges us to view the growth of global capitalism between 1750 and the early 1900s not as the Anthropocene, but the the Killing Age. Killing brought the world together and tore it apart, as profiteering warlords committed mass-scale slaughter of humans and animals across Africa, Asia, and the Americas. The newfound ease and profitability of killing created a disturbing network of global connections and economies, eliminating tens of millions of people and sparking an environmental crisis that remains the most urgent catastrophe facing the world today.
Drawing on years of scholarship and marshaling myriad sources across world history, The Killing Age turns our vision of past and present on its head, illuminating the Mortecene in all its horror—how it shaped who we are, what we value and fear, and the precarious present we inhabit today.
664 pages, Hardcover
Published November 25, 2025
15 people are currently reading
362 people want to read
Ratings & Reviews
Friends & Following
Create a free account to discover what your friends think of this book!
Community Reviews
Displaying 1 - 8 of 8 reviews
July 12, 2025
Book Review: The Killing Age: How Violence Made the Modern World by Clifton Crais
Rating: 5/5
Clifton Crais’ The Killing Age is a seismic rethinking of modernity—a work so rigorously researched and morally urgent that I found myself pausing every few pages to grapple with its revelations. By reframing the 18th and 19th centuries not as the dawn of progress but as the Mortecene (the “Killing Age”), Crais exposes the blood-soaked foundations of our global order. This isn’t just history; it’s a reckoning.
What stunned me most was Crais’ forensic tracing of violence as currency. His analysis of how guns, slavery, and extractivism intertwined—from the whaling industry’s mechanized slaughter to King Leopold’s Congo rubber terror—reveals capitalism’s original sin: profitability through annihilation. The chapter on American bison genocide (Extinguishing Nature) left me gutted, while his global lens (linking, say, Bengal’s famines to Confederate cotton) shattered my sense of these atrocities as isolated events. Crais’ prose is academic yet visceral, particularly when detailing how warlords weaponized free trade. I’ve never highlighted so many passages in a history book—each one a stark mirror to our climate crisis and inequality today.
If there’s a critique, it’s that the book’s panoramic scope (spanning five continents across 150 years) occasionally dilutes its emotional punch. A deeper dive into individual voices—enslaved people, Indigenous survivors—might have humanized the staggering death tolls cited. But this is a minor quibble. Crais’ appendices alone (tracking animal extinctions, climate shifts, and wealth disparities) are worth the price of admission, proving his thesis with chilling data.
By the epilogue, I felt both haunted and galvanized. The Killing Age doesn’t just diagnose our planetary crisis; it forces us to confront how its architects were rewarded. This is history as antidote to amnesia—and a call to dismantle the systems it exposed.
Thank you to The University of Chicago Press and Edelweiss for the advance copy. For readers of [Sapiens] or [The Dawn of Everything], Crais’ work is essential: a masterpiece that redefines how we understand power, progress, and survival.
Summary thoughts about this book:
-A bombshell of a book—Crais proves that modernity was built not on ideas, but on corpses.
-The Silent Spring of history: an unflinching exposé of how violence became the world’s most profitable industry.
-Forget the Anthropocene. After reading The Killing Age, you’ll see the 19th century for what it was: the Mortecene—the era when slaughter went global.
-Crais doesn’t just recount atrocities; he follows the money, revealing how genocide funded the Industrial Revolution.
-If you think capitalism ‘civilized’ the world, this book will shatter that myth—and leave you rethinking everything.
Rating: 5/5
Clifton Crais’ The Killing Age is a seismic rethinking of modernity—a work so rigorously researched and morally urgent that I found myself pausing every few pages to grapple with its revelations. By reframing the 18th and 19th centuries not as the dawn of progress but as the Mortecene (the “Killing Age”), Crais exposes the blood-soaked foundations of our global order. This isn’t just history; it’s a reckoning.
What stunned me most was Crais’ forensic tracing of violence as currency. His analysis of how guns, slavery, and extractivism intertwined—from the whaling industry’s mechanized slaughter to King Leopold’s Congo rubber terror—reveals capitalism’s original sin: profitability through annihilation. The chapter on American bison genocide (Extinguishing Nature) left me gutted, while his global lens (linking, say, Bengal’s famines to Confederate cotton) shattered my sense of these atrocities as isolated events. Crais’ prose is academic yet visceral, particularly when detailing how warlords weaponized free trade. I’ve never highlighted so many passages in a history book—each one a stark mirror to our climate crisis and inequality today.
If there’s a critique, it’s that the book’s panoramic scope (spanning five continents across 150 years) occasionally dilutes its emotional punch. A deeper dive into individual voices—enslaved people, Indigenous survivors—might have humanized the staggering death tolls cited. But this is a minor quibble. Crais’ appendices alone (tracking animal extinctions, climate shifts, and wealth disparities) are worth the price of admission, proving his thesis with chilling data.
By the epilogue, I felt both haunted and galvanized. The Killing Age doesn’t just diagnose our planetary crisis; it forces us to confront how its architects were rewarded. This is history as antidote to amnesia—and a call to dismantle the systems it exposed.
Thank you to The University of Chicago Press and Edelweiss for the advance copy. For readers of [Sapiens] or [The Dawn of Everything], Crais’ work is essential: a masterpiece that redefines how we understand power, progress, and survival.
Summary thoughts about this book:
-A bombshell of a book—Crais proves that modernity was built not on ideas, but on corpses.
-The Silent Spring of history: an unflinching exposé of how violence became the world’s most profitable industry.
-Forget the Anthropocene. After reading The Killing Age, you’ll see the 19th century for what it was: the Mortecene—the era when slaughter went global.
-Crais doesn’t just recount atrocities; he follows the money, revealing how genocide funded the Industrial Revolution.
-If you think capitalism ‘civilized’ the world, this book will shatter that myth—and leave you rethinking everything.
March 28, 2026
This is a well done and important book, but it is a difficult book to read. There has been a lot of history lately that has significantly changed how we think about prior times, actions, and events. Most significant for me has been Sven Becker’s work on Cotton (and Slavery) and, more recently, on the global history of capitalism. Robert Fogel’s work comes to mind as well. There is a large amount of valuable new work on history that has tended to recalibrate how we think of the past to work in the central role played by the less savory and more violent aspects of civilization. This is uncomfortable to read but much of the work is well done and persuasive.
The book of interest here by Clifton Crais is a more complicated argument, but clear enough. He is a historian and the book focuses on the idea is that the manufacture, sale, and distribution of weapons by manufacturers in the West was central to the spread of colonialism in Latin America, Africa, and Asia. How was it central? The weapons were the currency paid to local warlords to secure their support in obtaining whatever commodities were required to fuel the growth of colonialism - whether it was beaver pelts, ivory, palm oil, or human slaves. These exchanges were also linked to heavy loads of debt put upon the local leaders and they built their control yet tried to keep current with their colonial masters and overlords.
This process was largely one of outsourced control of colonial areas under the supervision of the leaders of chartered colonial corporations that exercised full governmental authority over an area without requiring the active intervention of the central colonial government and the imposition of direct governmental authority. This did not keep the corporate officers from getting rich in their colonial domains (like Clive in India).
This process was well under way in the 18th and 19th centuries and worked very well - until it did not work well. If yes, it also entailed incredible degrees of violence and suffering for the millions of locals who were affected and suffered from abuse and slavery through the Americas, Africa, and Asia.
By the mid-19th century, the stakes of global colonialism had risen, the weapons systems had improved, and the major nations, both democracies and empires, were drawn into direct intervention and competition in order to disarm the increasingly hard to manage warlords and secure western control of the increasingly valuable commodities.
A key argument of the book is that the weapons technologies and martial/managerial techniques honed in these processes turned back upon the Western Nations themselves and were in part responsible for the slaughter of WW1 and WW2. Their legacies continue today.
This book is fairly persuasive and makes one think twice about many of the standard pet explanations for the growth of nation states in the 19th century, in particular the US and the role of the expansion and taming of the West. The book also makes likes between industries like slavery and a variety of industries tied to the hunting and extermination of key animal groups seen as important for nascent industrialization. A prime example of this is whaling and its links to slavery. This puts Herman Melville and the great Moby Dick in an entirely new context that I need to reconsider.
This is a long book but I found it well worth reading.
IN PROCESS - MORE TO FOLLOW.
The book of interest here by Clifton Crais is a more complicated argument, but clear enough. He is a historian and the book focuses on the idea is that the manufacture, sale, and distribution of weapons by manufacturers in the West was central to the spread of colonialism in Latin America, Africa, and Asia. How was it central? The weapons were the currency paid to local warlords to secure their support in obtaining whatever commodities were required to fuel the growth of colonialism - whether it was beaver pelts, ivory, palm oil, or human slaves. These exchanges were also linked to heavy loads of debt put upon the local leaders and they built their control yet tried to keep current with their colonial masters and overlords.
This process was largely one of outsourced control of colonial areas under the supervision of the leaders of chartered colonial corporations that exercised full governmental authority over an area without requiring the active intervention of the central colonial government and the imposition of direct governmental authority. This did not keep the corporate officers from getting rich in their colonial domains (like Clive in India).
This process was well under way in the 18th and 19th centuries and worked very well - until it did not work well. If yes, it also entailed incredible degrees of violence and suffering for the millions of locals who were affected and suffered from abuse and slavery through the Americas, Africa, and Asia.
By the mid-19th century, the stakes of global colonialism had risen, the weapons systems had improved, and the major nations, both democracies and empires, were drawn into direct intervention and competition in order to disarm the increasingly hard to manage warlords and secure western control of the increasingly valuable commodities.
A key argument of the book is that the weapons technologies and martial/managerial techniques honed in these processes turned back upon the Western Nations themselves and were in part responsible for the slaughter of WW1 and WW2. Their legacies continue today.
This book is fairly persuasive and makes one think twice about many of the standard pet explanations for the growth of nation states in the 19th century, in particular the US and the role of the expansion and taming of the West. The book also makes likes between industries like slavery and a variety of industries tied to the hunting and extermination of key animal groups seen as important for nascent industrialization. A prime example of this is whaling and its links to slavery. This puts Herman Melville and the great Moby Dick in an entirely new context that I need to reconsider.
This is a long book but I found it well worth reading.
IN PROCESS - MORE TO FOLLOW.
January 13, 2026
The Killing Age is one of those books I really wanted to like. The main idea presented, that large-scale violence has played a huge role in shaping the modern world, is genuinely interesting and, honestly, pretty convincing on its own. There’s a strong case to be made that war, conquest, and military priorities have influenced everything from politics to technology to how societies are organized today.
Unfortunately, the book doesn’t fully live up to that potential.
Instead of exploring the topic from multiple angles, Crais sticks very tightly to one particular interpretation and doesn’t spend much time acknowledging that other historians might see things differently. A lot of complicated events are presented in a fairly one-note way, which makes the analysis feel more like an argument he wants to win than a conversation he wants to have.
That said, the research is clearly there. The bibliography is extensive, and it’s obvious a lot of work went into gathering sources. I just wish that same effort had gone into engaging with opposing viewpoints, because the subject really calls for more nuance than the book allows.
There are definitely sections that are thought-provoking, especially when the book looks at how violence becomes normalized through institutions and technology. But overall, the narrow focus and repetitive tone made it harder for me to stay fully engaged.
Not terrible by any means, but not as compelling or balanced as the premise deserved.
Thank you to NetGalley and the publisher for an early copy in exchange for an honest review. All opinions are my own.
Unfortunately, the book doesn’t fully live up to that potential.
Instead of exploring the topic from multiple angles, Crais sticks very tightly to one particular interpretation and doesn’t spend much time acknowledging that other historians might see things differently. A lot of complicated events are presented in a fairly one-note way, which makes the analysis feel more like an argument he wants to win than a conversation he wants to have.
That said, the research is clearly there. The bibliography is extensive, and it’s obvious a lot of work went into gathering sources. I just wish that same effort had gone into engaging with opposing viewpoints, because the subject really calls for more nuance than the book allows.
There are definitely sections that are thought-provoking, especially when the book looks at how violence becomes normalized through institutions and technology. But overall, the narrow focus and repetitive tone made it harder for me to stay fully engaged.
Not terrible by any means, but not as compelling or balanced as the premise deserved.
Thank you to NetGalley and the publisher for an early copy in exchange for an honest review. All opinions are my own.
September 6, 2025
Flawed Premise And Weirdly Exacting Time Selection Move Interesting Premise To Garbage Narrative. This is one of those books that I *wanted* to like. I *strongly* believe, based on my own historical studies over the years, that there is a truly strong case to be made for how violence has shaped the modern world in ways that most humans alive today simply aren't aware of. There is a case to be made for how violence and conquest shape almost literally every facet of everything we currently know, up to and including the most bleeding edge sciences all largely having their origins in military research and applications - including all of computing and very nearly everything we as humanity are doing both in astronomy and in particle physics.
Unfortunately, this book doesn't even begin to attempt to make that case.
Instead, this is yet another anti-capitalist polemic wherein a "historian" attempts to reframe history... and yet provides a bibliography one would typically expect from a more mundane and well trod "this is what happened at this event" type history book. In other words, it is *far* from meeting the Sagan Standard of "extraordinary claims require extraordinary evidence". And yet, at roughly 22% bibliography (in addition to several more pages of front matter listing many dozens of people and events covered in the text), this text sufficiently meets my 20-30% documentation expectations for nonfiction books generally, so actually doesn't lose a star there. Note even here though that while there is technically enough bibliography, it is also extremely cherry picked to show exactly the narrative Crais is trying to frame without ever even hinting at other possible interpretations of the events at hand.
No, the two star deductions are distinct enough (in my mind at least) to warrant two separate deductions, but also linked in that they form the basis of how Crais approaches his entire narrative.
For one, Crais blames all of captialism's rise on slavery... without even going into the 20th century to try to frame the various labor debates there as also slavery or even including the rise of mass incarceration or fast fashion or any other well known labor abuses as also slavery, choosing to instead end his narrative at the end of the 19th century. Thus, even though Great Britain ended slavery relatively early in the time period Crais does choose to focus on and the US fought a civil war near the end of it to force the end of slavery... Crais still blames all of capitalism's ills on, according to him, capitalism being based on slavery and absolutely nothing else.
For another, and yes, I hinted at this above, Crais is oddly specific in his choice of time period and even areas of focus, choosing to examine only Great Britain and the United States and to begin specifically in 1750 with the publication of Adam Smith's The Wealth of Nations and end at the end of the 19th century, well before capitalism *really* took off... and yet also before communism caused the deaths of literally millions of people itself... often via direct State violence. This odd specificity allows Crais to openly ignore other violences even within the period he chooses to examine, such as the Napoleonic Wars.
There is great promise in a book that truly and fully explores the history of human violence in its totality and shows how that violence has created and shaped our modern world as we know it.
I simply wish Crais had made even a modicum of an attempt at writing such a history. Perhaps this book would have been better with a different title and more honest and specific premise?
Not recommended.
Unfortunately, this book doesn't even begin to attempt to make that case.
Instead, this is yet another anti-capitalist polemic wherein a "historian" attempts to reframe history... and yet provides a bibliography one would typically expect from a more mundane and well trod "this is what happened at this event" type history book. In other words, it is *far* from meeting the Sagan Standard of "extraordinary claims require extraordinary evidence". And yet, at roughly 22% bibliography (in addition to several more pages of front matter listing many dozens of people and events covered in the text), this text sufficiently meets my 20-30% documentation expectations for nonfiction books generally, so actually doesn't lose a star there. Note even here though that while there is technically enough bibliography, it is also extremely cherry picked to show exactly the narrative Crais is trying to frame without ever even hinting at other possible interpretations of the events at hand.
No, the two star deductions are distinct enough (in my mind at least) to warrant two separate deductions, but also linked in that they form the basis of how Crais approaches his entire narrative.
For one, Crais blames all of captialism's rise on slavery... without even going into the 20th century to try to frame the various labor debates there as also slavery or even including the rise of mass incarceration or fast fashion or any other well known labor abuses as also slavery, choosing to instead end his narrative at the end of the 19th century. Thus, even though Great Britain ended slavery relatively early in the time period Crais does choose to focus on and the US fought a civil war near the end of it to force the end of slavery... Crais still blames all of capitalism's ills on, according to him, capitalism being based on slavery and absolutely nothing else.
For another, and yes, I hinted at this above, Crais is oddly specific in his choice of time period and even areas of focus, choosing to examine only Great Britain and the United States and to begin specifically in 1750 with the publication of Adam Smith's The Wealth of Nations and end at the end of the 19th century, well before capitalism *really* took off... and yet also before communism caused the deaths of literally millions of people itself... often via direct State violence. This odd specificity allows Crais to openly ignore other violences even within the period he chooses to examine, such as the Napoleonic Wars.
There is great promise in a book that truly and fully explores the history of human violence in its totality and shows how that violence has created and shaped our modern world as we know it.
I simply wish Crais had made even a modicum of an attempt at writing such a history. Perhaps this book would have been better with a different title and more honest and specific premise?
Not recommended.
August 26, 2025
The Killing Age: How Violence Made the Modern World, by Clifton Crais, is a well-researched reassessment of what has become known as the Anthropocene, but centering violence and weapons rather than the concept often thought of as "progress."
This is one of those books that will, and should, make you uncomfortable and want to counter some of the arguments. But if you look at the research, the events that did indeed play major roles in making this world what it is, you won't be able to honestly counter too many of them. Sure, you can rationalize a few things, especially if you or yours were the beneficiaries, but we both know that is all you'll be doing, rationalizing as cover-up.
Our discomfort shouldn't be taken so personally that we seek to hide from this very persuasive argument but rather try to better understand why we as human beings are this way and what we might be able to do to make things better. If we as a species survive, what kinds of infrastructure, not just material but governmental and cultural, can we incorporate so that the world, not just humans, survive and flourish for a long time? Is there anything we can actually expect to accomplish when those currently in power take such enjoyment in inflicting harm on people and the environment?
This can be read as primarily a history book coming from a different perspective and making a counterargument for how and why the world has changed (I won't say evolved, that often implies a positive change). As such it is a fascinating book that could both enlighten and offer some ideas for further reading and research.
I prefer to read this as history with a purpose. Certainly not prescriptive, I'm not sure what one could put down briefly that cod be such. But we are warned throughout to look for two trails: money (or lust for profit) and weaponry (whether building up or sending off to increase profit). While a single unified plan to confront and reverse our destructive tendencies would be wonderful, it really seems like people locally and regionally will need to make stands where they are against whatever specific ills they have while looking for similar groups elsewhere to gradually form larger coalitions, mutual cooperation to attack the various sources of our self-destruction. So I guess you could say I think this can serve as a call-to-action. One of the difficult aspects is that there isn't much in the way of previous success stories to build on, so we need to be creative and find ways to make positive change even though our "leaders" have no interest in us or the world beyond what it can add to their own feeble sense of entitlement.
Highly recommended for readers of history, as well as those who want to better understand why we're destroying our planet and everything on it so gleefully. What we do with this information, whether to make positive change or just add an extra lecture to the syllabus we're making, is up to us. I vote for positive action against passive support.
Reviewed from a copy made available by the publisher via NetGalley.
This is one of those books that will, and should, make you uncomfortable and want to counter some of the arguments. But if you look at the research, the events that did indeed play major roles in making this world what it is, you won't be able to honestly counter too many of them. Sure, you can rationalize a few things, especially if you or yours were the beneficiaries, but we both know that is all you'll be doing, rationalizing as cover-up.
Our discomfort shouldn't be taken so personally that we seek to hide from this very persuasive argument but rather try to better understand why we as human beings are this way and what we might be able to do to make things better. If we as a species survive, what kinds of infrastructure, not just material but governmental and cultural, can we incorporate so that the world, not just humans, survive and flourish for a long time? Is there anything we can actually expect to accomplish when those currently in power take such enjoyment in inflicting harm on people and the environment?
This can be read as primarily a history book coming from a different perspective and making a counterargument for how and why the world has changed (I won't say evolved, that often implies a positive change). As such it is a fascinating book that could both enlighten and offer some ideas for further reading and research.
I prefer to read this as history with a purpose. Certainly not prescriptive, I'm not sure what one could put down briefly that cod be such. But we are warned throughout to look for two trails: money (or lust for profit) and weaponry (whether building up or sending off to increase profit). While a single unified plan to confront and reverse our destructive tendencies would be wonderful, it really seems like people locally and regionally will need to make stands where they are against whatever specific ills they have while looking for similar groups elsewhere to gradually form larger coalitions, mutual cooperation to attack the various sources of our self-destruction. So I guess you could say I think this can serve as a call-to-action. One of the difficult aspects is that there isn't much in the way of previous success stories to build on, so we need to be creative and find ways to make positive change even though our "leaders" have no interest in us or the world beyond what it can add to their own feeble sense of entitlement.
Highly recommended for readers of history, as well as those who want to better understand why we're destroying our planet and everything on it so gleefully. What we do with this information, whether to make positive change or just add an extra lecture to the syllabus we're making, is up to us. I vote for positive action against passive support.
Reviewed from a copy made available by the publisher via NetGalley.
February 4, 2026
Not completely on board with the author's premise here. Crais limits the scope of the interesting subject matter to a particular time frame and emphasizes the whole sordid global colonial enterprise as central to the 'morticene' or killing age. Surely an interesting viewpoint, but there are a lot more angles to attack from; is the whole killing age not an epiphenomenon of a surging global population that is evermore more mobile and hungry for material wealth? For a more considered account of human cruelty, be sure to check out: The Better Angels of Our Nature: Why Violence Has Declined.
April 23, 2026
Sort of a revisionist account of violence globally between 1750 and 1900 with an emphasis on climate change and non-human animal deaths. It’s an interesting idea but some of the author’s claims seem controversial. He calls the arms industry and other harmful industries like slavery or natural resource extraction an “immoral economy.” No doubt many abolitionists and pacifist activists felt this way in the 19th century, but there were also many defenders of these industries at the time. This was an age where European powers did brutally exploit its colonies and generated levels of wealth hitherto unknown. I would recommend this book to people who want to understand the harm to indigenous people and the environment through colonialism, slavery, forced labor, and displacement.
November 17, 2025
Really awful, don't waste your time.
Not really a history book more a cyclical propaganda tome devoid of scholarship and persuasion
Not really a history book more a cyclical propaganda tome devoid of scholarship and persuasion
Displaying 1 - 8 of 8 reviews