Razib Khan One-stop-shopping for all of my content

March 24, 2020

To beat the dragon be the dragon

Filed under: History,Roman History,rome,Sulla — Razib Khan @ 1:52 am

In The Fate of Rome: Climate, Disease, and the End of an Empire Kyle Harper argues that the Plague of Cyprian, between 249 to 262 A.D., served as a massive exogenous shock to the Roman Empire that changed history. Harper observes that the structures of Roman society were reordered in the face of near collapse and exhaustion due to the onslaught of disease. The Plague of Cyprian, at least in Harper’s telling, plays a major role in the rise of Christianity and the fading away of the traditional religion (more through the inability of the old pagan institutions to persist in the face of social instability as opposed to a crisis of faith).

But the change was more than cultural. It is well known that Augustus, the first of what we call Roman Emperors, styled himself Princeps, and maintained the external fiction that he restored the republic. The term Imperator was not applied regularly to Roman Emperors until the reign of Vespasian, in the last quarter of the 1st century A.D., nearly a century after Augustus came to power. But even then the rulers of the Roman world maintained a conceit and fiction that they were scions of the old republican world, the first among the aristocrats. This was certainly true of Marcus Aurelius, who famously styled himself something of a philosopher-king as well.

After the disastrous reign of Marcus Aurelius’ son, Commodus, the dynasty founded by Septimius Severus moved in a more nakedly autocratic direction. Severus notably presented laws to the Senate as expressions of his fiat will. But Severus was from the old aristocracy of Rome. He underwent the cursus honorum under the Antonines.

The true shift came during the late 3rd-century and the rise of the Tetrarchs. These military rulers, who came out of the barracks of the Illyrian legions, ushered in the Dominate. This is the despotic later phase of the Roman Empire and derives from the fact that Diocletian added dominus, lord or master, to one of his titles. Diocletian and his successors did not see the need for the pretense that their world was that of the Republic. It was fundamentally different. They accrued to themselves the powers and styles of despotic eastern rulers.

Why? The shock of the Plague of Cyprian induced instability in the Roman world, which a powerful ruler stabilized. But according to Peter Heather in The Fall of the Roman Empire the Romans were reacting to the emergence of the Sassanians, who had reconfigured Persia to be a more formidable rival to Rome.* The irony here is that just the Persians became the great enemy of Rome, the Emperors of Rome began to resemble their eastern rivals in their external form and internal self-identity.

* Adrian Goldsworthy disagrees that Sassanian Persia was so formidable, ascribing the military parity more to Roman decay than the rise of Iran.

November 7, 2019

Syrian Orontes has long since dried up, to be replaced by the Tiber once more

Filed under: Roman History — Razib Khan @ 6:04 pm


The paper is out, Ancient Rome: A genetic crossroads of Europe and the Mediterranean:

Ancient Rome was the capital of an empire of ~70 million inhabitants, but little is known about the genetics of ancient Romans. Here we present 127 genomes from 29 archaeological sites in and around Rome, spanning the past 12,000 years. We observe two major prehistoric ancestry transitions: one with the introduction of farming and another prior to the Iron Age. By the founding of Rome, the genetic composition of the region approximated that of modern Mediterranean populations. During the Imperial period, Rome’s population received net immigration from the Near East, followed by an increase in genetic contributions from Europe. These ancestry shifts mirrored the geopolitical affiliations of Rome and were accompanied by marked interindividual diversity, reflecting gene flow from across the Mediterranean, Europe, and North Africa.

If you don’t have access to the paper, the supplements are very good, with lots of visualizations.

The figure above summarizes the main clear dynamic:  the period of cultural and genetic cosmopolitanism of the Imperial period turned out to be ephemeral. The authors express a bit of surprise that the cosmopolitanism of Roman genetics during the Imperial period seems to manifest itself in an ‘eastward’ shift, and hypothesize that this is due to the greater population density of the eastern provinces.

This is almost certainly true.

The western focus of the early Roman Empire was somewhat at odds with the reality that the wealthiest and most populous domains were located in the eastern Mediterranean. The shocks of the 3rd-century resulted in an eastward orientation because that’s where the largest cities and tax base were. The Greek-speaking east, in particular, continued to provide the intelligentsia even throughout the Classical period, and due to the wealth of eastern cities, it is plausible that the mercantile elite of the capital often had eastern roots. The prevalence of Greek inscriptions in burials also is strongly indicative of eastern people in the capital.

That’s all to be expected. But what happened after the fall of Rome? The evidence above shows a western and northern shift. Though the proximal populations that contributed to this shift are somewhat different, overall the distal ancient components (e.g., “Neolithic”) return to frequencies that are closer to Iron Age Latium than the Roman Imperial phase. How did this happen?

Ancient DNA is a great window into the past, but it needs to be synthesized with an understanding of historical and anthropological processes. The Rome of the 400s was still a massive city, only marginally off its imperial peak in terms of population. But the Rome of 600 A.D. was a city filled with emptiness. What happened? A combination of the wars of the 6th-century, which are recorded to have depopulated much of Italy, and the overall decentering of Rome from the Mediterranean system after the ending of the Western Empire, probably resulted in the inevitable contraction of the Eternal City.

Of course, Rome grew again over the centuries. But the new Romans were not the same Romans as those of the Roman Empire, who left few descendants. In addition to far off cosmopolitans, the bulk of the population was probably derived from northern Lazio and southern Tuscany. Rural people whose genetic makeup resembled the Iron Age Italians from whom they descended.

This answers the question that people have been asking for decades: are modern Romans descended from the people of Republican Rome or Greeks and Syrians who transformed themselves into Romans? The answer is neither. Modern Romans descend from Italian peasants, who were less impacted by the predations of the Goths and Byzantines, and had higher fertility than urban dwellers even in peaceful times.

Which brings me to a second paper in the same issue of Science, The Church, intensive kinship, and global psychological variation:

There is substantial variation in psychological attributes across cultures. Schulz et al. examined whether the spread of Catholicism in Europe generated much of this variation (see the Perspective by Gelfand). In particular, they focus on how the Church broke down extended kin-based institutions and encouraged a nuclear family structure. To do this, the authors developed measures of historical Church exposure and kin-based institutions across populations. These measures accounted for individual differences in 20 psychological outcomes collected in prior studies.

The results are not that surprising, though the statistical rigor of the paper is impressive. I first encountered the idea about the instrumental role of the Western Church in imposing a new family order in Western Europe in Adam Bellow’s In Praise of Nepotism (others may have heard about this via HBD Chick). Bellow offers a very simple explanation: the early Roman Catholic Church used its ideological power to prevent the emergence of powerful lineage groups. More concretely, limiting marriage prospects of elite lineages increased the probability that properties of wealthy families would be given to the Church as a gift.

In some ways, this paper has nothing to do with the first. But note that the period when the Western Church began to transform the familial structure of Western Europe is at the end of the Roman Empire. Between the 6th and 9th centuries the Roman Church was a particularly cosmopolitan institution in a rapidly barbarizing Western Europe. In the 7th and early 8th century, there were a series of ethnically Syrian Popes, to give one example. As the post-Roman world in the West began to devolve into localism, the Western Church remained international. Global.

Consider then this Late Roman institution, the Western Church, a locus of urbane cosmopolitanism reflecting the civilian values of the ancient Roman aristocracy, surrounded by a rising tide of unlettered barbarism in the form of marginally Christianized Lombards and their ilk. This cultural tension during these centuries of Late Antiquity may lay at the root of the ideological program promoted by the Western Church against the ascendent barbarian elites which had inherited the mantle of Rome.

Finally, a map within this paper showing the role of kinship in modern societies illustrates a striking pattern:

In Victor Lieberman’s Strange Parallels he asserts that Southeast Asia, like Europe, is part of a “protected zone” against the predations of the steppe. As such, it retained stability and continuity which allowed for the emergence of modern nation-states. Notice that Theravada Southeast Asia has a low kinship index, just like Europe (Vietnam, like China, has a high kinship index probably because of Confucianism’s focus on family as the atomic unit of society). Japan, also part of the “protected zone”, has a low kinship index.

It strikes me that exploring the role of institutions and historical contingency in these regions in decreasing the importance of familialism might be something that needs to be done. With that being said, the fact that the Western Church inherited Greco-Roman aversion to polygamy and innovated its own aversion to consanguinity resulted in a very unique familial configuration in Western Europe. Monogamous. Deemphasizing the extended kinship group.

We live in a time when some people would assert that “Western civilization” is a racist term. But it seems to me that these tendencies within Western civilization are highly correlated with flourishing and innovative societies.

December 29, 2018

Making Sense of Roman History: A Reading List

Filed under: Books,Roman History — Razib Khan @ 1:42 am

Inspired by Tanner Greer, I’ve decided to put together a list of books that I think will useful to understanding the Romans from the perspective of a non-specialist without a background in Latin, or Classics more broadly (I am in this category obviously).

First, I’m a big fan of Michael Grant’s History of Rome. Grant was a historian who wrote a great many books for the popular audience, and his History of Rome is a comprehensive survey. I’ve read it multiple times. Mary Beard’s SPQR: A History of Ancient Rome is a more contemporary take which covers a similar period. But I’m not sure it’s as useful if you have less background than Grant’s more traditional sequence.

Robin Lane Fox’s The Classical World: From Homer to Hadrian covers a lot more than Rome, but what it does cover that is Greek is essential to understanding Rome.

Adrian Goldsworthy’s The Fall of Carthage: The Punic Wars 265-146 BC is a good read on a classic topic. Goldsworthy is a military historian, and it shows. To be frank I haven’t read many treatments of the republican period, since so much of it is back-loaded to the decades before the principate. But Goldsworthy’s Caesar: Life of a Colossus illuminates this critical juncture in Roman history well enough.

There are so many nearly novel-like treatments of figures from the Second Triumvirate and the Julio-Claudians that I’m not going with anything conventional: try Agrippina: Sex, Power, and Politics in the Early Empire. Colin Wells’ The Roman Empire focuses on the imperial peight up until the middle of the 3rd century. If you’ve read the survey above then you know why Gwyn Morgan’s 69 A.D.: Year of Four Emperors is important to read.

I think biography is a pretty good way to get a sense of particular periods. With that in mind, Frank McLynn’s Marcus Aurelius: A Life and David Potter’s Constantine the Emperor are useful, if a bit plodding and overmuch for the casual student.

The Fall of Rome: And the End of Civilization, The Fate of Rome: Climate, Disease, and the End of an Empire, and The Fall of the Roman Empire: A New History of Rome and the Barbarians are all critical contemporary analyses of the end the Roman polity. Written from an archaeological, environmental scientific, and narrative historical angles, they give different viewpoints on the same questions. These are all more or less responses to the sort of work written by Peter Brown a generation earlier, The Rise of Western Christendom: Triumph and Diversity, A.D. 200-1000, which argues against the idea of the fall. From a different perspective (the barbarian), The End of Empire: Attila the Hun & the Fall of Rome, though to be frank this book is as much about Aetius as it is about Attila.

Life and Leisure in Ancient Rome is one of the many books on the topic of “daily life” during this period and place. You should read at least one of these. I’m not a humanist in Tanner’s league, so you won’t get poetry recommendations from me, but Aupelius’ The Golden Ass is the only complete surviving Latin novel. It’s rather weird. You surely know the list of eminences of the Latin poets, but Ovid’s Metamorphoses induced less labor than Virgil’s Aeneid. I recall thinking Virgil was a bit too “try hard.” Unlike The Fall of Rome: And the End of Civilization and History of Rome, both of which I’ve read more than half a dozen times front to back, with literature I usually read once, and don’t retain too much. I’m a Philistine!

Rome and China: Comparative Perspectives on Ancient World Empires and Rome and Jerusalem: The Clash of Ancient Civilizations are interesting comparative analyses. If you had to pick the two, I’d go with the first, but that’s because purely intellectual histories are not as interesting to me.

Historical fiction isn’t always accurate, but it really brings the dramatis personae alive. Colleen McCoullough’s First Man in Rome series is excellent, especially the first few novels. Everyone knows Robert Graves’ I, Claudius. But my teenage-self really enjoyed Allan Massie’s Let the Emperor Speak, about Augustus, and Tiberius: The Memoirs of the Emperor. Gore Vidal’s Julian: A Novel is well written and engaging, though a little light on history (not surprisingly there is a lot of editorializing by Vidal through Julian).

You have in some way read the works of Seutonius,Tacitus, and Livy because they are the foundation for so much of the narrative works written today. They are also the source material for fiction and dramatizations. If you want to “go back to the sources”, give Ammianus Marcellinus a try. He’s overlooked, and he’s excellent.

Rodney Stark wrote The Rise of Christianity: How the Obscure, Marginal Jesus Movement Became the Dominant Religious Force in the Western World in a Few Centuries back when he was a scholar and not a polemicist. I’m skeptical of some of his conclusions, but his thinking here is rigorous.Robin Lane Fox’s Pagans and Christians is complementary to The Rise of Christianity. Finally, Michelle Salzman’s The Making of a Christian Aristocracy: Social and Religious Change in the Western Roman Empire is worth a deep read.

Some of the New Testament is interesting too. I especially think that the material attributed to St. Paul, a Roman citizen, is worth reading.

And finally, St. Augustine is worth a read. City of God is interminably long, but Confessions is more compact, and the beginning of a whole genre which eventually culminated in James Frey.

November 16, 2018

Random and inevitable forces in world history: the 6th century

Filed under: History,Roman History — Razib Khan @ 6:19 pm

In Science Anne Gibbons reports on new ice-core evidence for why the middle of the 6th century A.D. was so difficult in much of Europe:

Historians have long known that the middle of the sixth century was a dark hour in what used to be called the Dark Ages, but the source of the mysterious clouds has long been a puzzle. Now, an ultraprecise analysis of ice from a Swiss glacier by a team led by McCormick and glaciologist Paul Mayewski at the Climate Change Institute of The University of Maine (UM) in Orono has fingered a culprit. At a workshop at Harvard this week, the team reported that a cataclysmic volcanic eruption in Iceland spewed ash across the Northern Hemisphere early in 536. Two other massive eruptions followed, in 540 and 547. The repeated blows, followed by plague, plunged Europe into economic stagnation that lasted until 640, when another signal in the ice—a spike in airborne lead—marks a resurgence of silver mining, as the team reports in Antiquity this week.

Kyle Harper, author of the excellent The Fate of Rome: Climate, Disease, and the End of an Empire, is quoted in the piece. It’s curious to me to observe the stochastic and correlated events in this particular story.

I assume that volcanic mega-eruptions occur in a pattern defined by a Poisson distribution. That is, they are rare and random events. One thing about the Poisson distribution is that the events tend to cluster together more than human intuition would predict based on what we think might occur when we hear “random events.” Those with more paleoclimate knowledge that I can evaluate this, but it seems that massive eruptions that occurring so close in time are going to be rare indeed, but, they will happen now and then.

That’s the random part. The outbreak of plague is probably less random. In Europe, the plague faded in the early modern period. Though people disagree about the reasons, modern developed societies where people are more well-fed are probably less susceptible to it (as well as low-density hunter-gatherer or pastoralist populations). As Peter Turchin has pointed out only one sitting European monarch died during the Black Death of the bubonic plague, even as 30-60% of the local population succumbed. It seems likely that extremely difficult conditions for agriculture, and the consequent malnutrition, made the spread of plague through vulnerable populations much more likely.

A major consequence of the calamities of the mid-6th century is the reconquest of the West Roman Empire under the push from Justinian and his heirs lost steam. Unlike in China, the Roman system was never recreated in full. Many explanations have to do with the violence of the Gothic Wars, or the inability of East Roman power to expand west while dealing with a more vigorous Persia to the east. We can’t rerun the experiment, but the above volcanic eruptions suggest that the likelihood of total reconquest took a major hit because of an event that was not inevitable.

Remember that the Roman state recovered by near total unwinding in the middle of the 3rd century.

Though we will never resolve the issue of whether the fall and collapse of the Roman Empire was inevitable and its reassembly impossible, by looking in totality at volcanic events and seeing how it correlates with state-formation or collapse, and social complexity, we may get a sense of the nature of the balance of endogenous cyclical forces and exogenous random shocks in the rise and fall of polities. By endogenous cyclical forces, I’m referring here to social cohesion and elite unity, which over time degrades and decays. As states and societies fracture and a new cycle of integration begins anew. I suspect that the exogenous shocks occur periodically, but that if they slam a society at its peak, then the social structure may be able to absorb the shock. In contrast, societies under stress collapse due to unexpected perturbations.

May 24, 2018

The souls of peoples gone

Filed under: Demographics,Pots not Peoples,Roman History,rome — Razib Khan @ 11:14 pm



Stonehenge was first erected around 3100 BC, though the timber was only replaced with stone in 2600 BC. The great monument was a product of the Late Neolithic in Britain. Ancient DNA today tells us that these people were distantly related to the modern Sardinians, and derive from a wave of farmers that radiated out of Anatolia across much of Europe.

About a century after the stone form of Stonehenge was erected, prehistoric Britain was culturally and genetically transformed. In the space of a few centuries after 2500 BC there was nearly a ~90% genetic turnover, and a new people more closely related to Northern Europeans in Germany and further east became ascendant. The majority of the ancestry in Britain today probably derives from this migration period.

And yet the new people continued to utilize Stonehenge for over 1,000 years. Clearly, they co-opted a monument erected by their predecessors and maintained its significance across an enormous cultural disruption.

This is on my mind because on the episode of The Insight recorded with Patrick Wyman (it will probably drop in June) we talked extensively about Roman demography. And one of the peculiarities of 2013’s The Geography of Recent Genetic Ancestry across Europe is that Italy has a lot of deep population structure. From the paper:

There is relatively little common ancestry shared between the Italian peninsula and other locations, and what there is seems to derive mostly from longer ago than 2,500 ya. An exception is that Italy and the neighboring Balkan populations share small but significant numbers of common ancestors in the last 1,500 years, as seen in Figures S16 and S17. The rate of genetic common ancestry between pairs of Italian individuals seems to have been fairly constant for the past 2,500 years, which combined with significant structure within Italy suggests a constant exchange of migrants between coherent subpopulations.

The implication here is that there’s population structure deeper than the Roman period. When I first saw these results I was surprised. Looking at genome-wide data I was pretty sure that most of the modern Italian population dated to the Roman Republican period, but I was not expecting provincial level substructure. It was like telling me that the Samnites and Umbrians were still with us!

But what about the great cosmopolitan cities of Neopolis, Rome, and Ravenna? Some commenters on this blog routinely get frustrated when I dismiss the textual and epigraphic evidence of massive migration into the Italian peninsula during the height of the Roman Empire. Actually, I believe that this migration occurred. I just do not believe it was particularly impactful genetically today. Though my general outlook on this issue goes back over ten years (in part thanks to the suggestion of Greg Cochran), I believe the issue here is that cities are such incredible demographic sinks.

Roman urban cosmopolitanism was parasitic on migration. Demographically it was never self-sustaining. In fact, as Patrick points out urban areas probably did not see sustained above replacement reproduction anywhere in the world before about 1900, with the emergence of germ theory and massive public sanitation works, especially in the United States. This is evident in books as diverse as Kyle Harper’s The Fate of Rome and The Rise and Fall of American Growth.

So did Roman urban civilization leave nothing to posterity? On the contrary. Like much of Rodney Stark’s work in the last twenty years Cities of God is needlessly polemical and oftentimes unscholarly*, it gets at the reality that Christianity was fundamentally an urban cult. It was brought to Italy by people from the Eastern Mediterranean, Jews and Greeks. In its early period it was dominated by urban cosmopolitans. Some of the sermons in urban churches even castigated rural peasants  as pagan beasts of the field.

Christianity was an international religion with foreign origins, and like many elite cultural constructions of the pre-modern oikoumene its existed operationally as a social network across the various cities around which elites congregated. In some ways the vast sea of villages which filled in the landscape were untouched by many of the cultural innovations occurring in the cities. A Neolithic person might be confused by some aspects of Roman village life (in particular, access to standardized manufactured goods), but they would be totally flabbergasted by the city of Rome.

Over the 200 years between 400 AD and 600 AD the population of Rome probably went from ~500,000 to ~50,000. The decline of the Western Empire and the period of the Gothic Wars choked off the economic subsidies which could maintain the city’s population by drawing newcomers. And yet the Bishop of Rome, the Pope, remained in the city. If Patrick and I are correct then medieval Rome was repopulated by the descendants of peasants from Lazio, the hinterlands around the city.

Some scholars, albeit often from a partisan Protestant viewpoint, have suggested that the Western Christian Church of the early Middle Ages did not truly Christianize the peasantry. Whether this is true or not, it does seem to correct to say that deeply rooted popular Christianity took many centuries to become pervasive in rural areas. Despite their relative decline in the medieval period, both substantively and in terms of cultural prestige, cities remained remained the stalwart redoubts of Roman Christianity. They were the braintrust of European civilization, even if they were not demographically self-sustaining.

To a great extent the last ten years has seen a refutation of “pots not peoples.” It turns out that many of the archaeological transitions seen in the physical record correlate with demographic changes inferred from genetic changes. And yet we know from history that some peoples and social groups which were highly influential left far less of a demographic footprint. I suspect that the rise of cities and complex polities transformed the “pots not peoples” calculus significantly.

* Google the fact that about ten years ago Stark was dismissing reports that Americans were getting more secular as wishful thinking by biased liberal scholars. Who do you really think had a bias with hindsight?

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