Tag Archives: science!

Next stop Iceland?

This post is about pre-Viking settlement in the North Atlantic, and here specifically the Faroe Islands. I originally stubbed this in September 2013, when I came across a relevant web report on Melissa Snell’s medieval history blog at About.com, but since that time it seems that they’ve stopped keeping archives over there, so that post is now gone. Actually this is good news, because it forced me to web-search out other reports, and the obvious one, on Nature World News, also includes a link to the actual article behind it all, so now I can write you something informed.1

View from the south-eastern extremity of Sandoy in the Faroe Islands, looking south down the chain

View from the south-eastern extremity of Sandoy in the Faroe Islands, looking south down the chain, and shamelessly plundered from a Faroes tourism site, linked through

The story is that new research proves that the Vikings were not the first colonisers of the Faroes. This, and the fact that this was being published in an geoscience rather than a specifically archæological or historical journal, gave me some faint worries about sensationalisation of research meant to prove other things, as we have seen here many times before, but in this case, as far as I can see, it’s the real deal. The team in question were doing a low-urgency rescue dig on a coastal site in danger of erosion at Á Sondum on the island of Sandoy in 2002 and 2006. The site had been dug once before in 1994 and had then shown a Viking longhouse at the bottom of its occupation sequence (which subsequently went all the way up to the 19th century, always on the same spot, not least, as the article says, because there just aren’t that many sensible places to put settlements on the Faroes).2 This time they located the long-house’s hearth, and then they kept going and found more beneath. It wasn’t much more, just peat ash with carbonised barley grains in it, but this is significant for two reasons: firstly, barley isn’t native to the Faroes, and secondly, peat-burning requires usually months of cutting, stacking and drying, and thus implies prolonged settlement, not just drop-in visits. And they duly had radio-carbon analysis done on the barley grains and got the figures you see below.

Calibration graph and stratigraphical context of the radio-carbon samples from Á Sondum, Sandoy

From Church, Arge, Edwards, Ascough, Bond, Cook, Dockrill, Dougmore, McGovern, Nesbitt & Simpson, “Vikings were not the first colonizers”, p. 230, larger version linked through

There are some things I don’t fully understand about this, mainly because to get these dates they used not individual samples but a combined sample, whose results were mathematically combined using a ‘weighted mean’. Well, weighted how? I feel we should be told more about this.3 Still, unless it was actually weighted outside the sample dates, which would be some strange new definition of ‘mean’ of which I was not previously aware, the results still seem fairly inarguable: two straigraphically separate episodes older than the Viking site by between half a century and three centuries. I feel that a mean critic might be able to handwave away the more recent result, given it was right under the hearth and the dates could just about overlap, but the older one is much harder to get around, which gives one that bit more confidence in the younger one.

A forbidding shoreline in South-Central Iceland

An even more forbidding shoreline in South-Central Iceland, apparently being slowly washed away by glacial outwash, as presented in Albert C. Hine, Jon Boothroyd & Dag Nummedal, “Glacial Outwash Plain Shoreline, South-Central Iceland”, Beach of the Month, Coastal Care 1st August 2013, linked through

So, OK, what does this all mean? Well, most obviously it means that someone was on Sandoy burning peat and scattering its ash on the shoreline well before the Vikings got there (and the study is extremely careful to emphasise that we have no idea who). What our authors are most excited about is that there were, previously, very small signs of pre-Viking occupation in the palaeobotanical record (which is to say, barley pollen had been found before in a hard-to-date but potentially early context4), and that having been able to pin it down with actual digging like this has big implications for other island chains where such out-of-place floral data has turned up but been dismissed. But it also made them think of what it makes me think of, which is an old question about whether anyone got to Iceland before the Vikings. There are stories about this in the texts, firstly bewildering seafaring fantasies like the Irish Navigatio Sanctio Brendani, in which Brendan and his monks find a series of fantastic islands in the Western Ocean while in search of Paradise, which they duly locate and are allowed to stop in for a bit before turning for home to spread the good word.5 Much effort has been spent on pinning actual Atlantic islands into his tale, but, to be cynical again, one might as well try the same exercise with The Voyage of the Dawn Treader, the islands are equally allegorical in both texts.6 But there is also the Íslendingabók of Ari Thorgillson, ‘The Book of the Icelanders’, in which Ari reports that the first Viking settlers on Iceland found white-clad men they called ‘papar’ there who fled before the Norsemen, leaving behind croziers and bells.7 That looks so like the kind of people St Brendan actually led that it’s usually been assumed these were Irish religious taking the spiritual exile thing unusually seriously. But there is no archæological evidence to show that Ari was doing anything more than making this up by extrapolation from stories about the Western Isles of Scotland or similar. The archæologists here are suitably cautious about fitting these older debates around their findings:

“Who were these earlier settlers, how many of them were there and where did they come from? Were they single ecclesiastical anchorites as described by Dicuil from Ireland, Late Iron Age groups of colonists from Atlantic Scotland or pre-Viking explorers from Scandinavia? Did they continue on to Iceland, or did the Faroes represent a temporary diasporal bottle-neck, requiring later Viking seafaring technology to be able to sail to Iceland and Greenland, and importantly to sail back? To answer these questions, more and better-preserved pre-Viking Faroese archaeological sites need to be identified, excavated and analysed.”8

To that, I would only say that the Vikings’ seafaring technology was perfected well before the Viking disapora started, so that might not be the significant limitation, but the Faroes radio-carbon dates are still very early and the authors’ caution here is absolutely commendable.9 What they do do, however, is establish an excellent idea of where to look for such remains in island contexts, and that gives me hope that Iceland might, indeed, be the next stop, just because it would be fun finally to have some kind of archæology to set against Ari’s stories. I’ll let the authors of the article have the last word, though, because they have bigger things in mind than my antiquarianism, and will myself just finish by saying that I wish all science publications with historical impact could manage it as well as these writers have:

“This detailed examination at the base of coastal erosion archaeological sections was successfully used to identify the first archaeological sites of Mesolithic date in the Western Isles of
Scotland. A similar palynological argument for early human settlement was proposed for the ‘invisible Mesolithic’ of the Western Isles, where small-scale clearance episodes evident in pre-Neolithic pollen sequences, coupled with a rise in microscopic charcoal, led researchers to suggest that hunter-gatherer fire ecology accounted for these disturbances, despite the lack of any Mesolithic archaeological sites in the island chain. In the Faroes and the Western Isles of Scotland, small-scale perturbations in pollen sequences were interpreted as ephemeral human occupation events in periods prior to the orthodox landnám [‘land-taking’] events attested by the substantial settlement record of structures, dating to the Viking and Neolithic periods respectively. In both cases, the palaeoecological interpretations were eventually proved to be correct on discovery of ephemeral archaeological remains of pre-landnám date at the base of large coastal erosion archaeological sections and this raises intriguing issues about perturbations in palaeoenvironmental sequences prior to orthodox landnám chronological horizons in other island systems elsewhere in the North Atlantic and across the world, as in the Pacific."10

1. Mike J. Church, Símun V. Arge, Kevin J. Edwards, Philippa L. Ascough, Julie M. Bond, Gordon T. Cook, Steve J. Dockrill, Andrew J. Dugmore, Thomas H. McGovern, Claire Nesbitt, Ian A. Simpson, “The Vikings were not the first colonizers of the Faroe Islands” in Quartnerary Science Reviews Vol. 77 (Amsterdam 2013), pp. 228-232, DOI: 10.1016/j.quascirev.2013.06.011. Assigning author order on that must have taken nearly as long as the project itself…

2. Ibid. pp. 228-230; the previous dig, led by the second author here, seems not to have been published.

3. Rather than tell us about it, they refer to two other studies, P. J. Ashmore, “Radiocarbon dating: avoiding errors by avoiding mixed samples” in Antiquity Vol. 73 (Edinburgh 1999), pp. 124-130, which you’ll notice is a vote against doing this, and Ascough, Cook & Dugmore, “North Atlantic marine 14C reservoir effects: Implications for late-Holocene chronological studies” in Quarternary Geochronology Vol. 4 (Amsterdam 2009), pp. 171-180, DOI: 10.1016/j.quageo.2008.12.002, which presumably isn’t.

4. Here they cite a whole rook of stuff, the most recent of which is K. J. Edwards & D. M. Borthwick, “The pollen content of so-called ‘ancient’ field systems in Suethuroy, Faroe Islands, and the question of cereal cultivation” in S.-A. Bengtson, P. C. Buckland, P. H. Enckell & A. M. Fosaa (edd.), Dorete – Her Book – Being a Tribute to Dorete Bloch and to Faroese Nature, Annales Societatis Scientiarum Færoensis, Supplementum LII (Tørshavn 2010), pp. 96-116.

5. I’m not sure what the preferred edition of the Navigatio is these days but in trying to find out I have found Guy Vincent (ed.), “Navigation de Saint Brendan : texte latin et traduction”, http://www.utqueant.org/net/doc.3.Bren.II.html, last modified 24th October 2005 as of 26th August 2014, which will probably do. There is a good English translation in J. F. Webb (transl.), Lives of the Saints (Harmondsworth 1965), pp. 31-68, repr. in D. H. Farmer (ed./transl.) & Webb (transl.), The Age of Bede (Harmondsworth 1983), pp. 231-267 even though the text is likely from a century after Bede.

6. There are various studies on the Atlantic world implied by the text in John W. De Courcy & David Sheehy (edd.), Atlantic Visions (Dun Laoghaire 2009), which I will admit straight up I have never seen but just now pulled out of a database; any other suggestions?

7. There seems to be an edition of Íslendingabók by Guðni Jónsson online here but I have no idea how good it is; again, any better references would be appreciated. The standard translation, Siân Grønlie (transl.), Íslendingabók; Kristni Saga. The Book of the Icelanders; The Story of the Conversion (London 2006), pp. 3-34, is online here in PDF.

8. Church, Arge, Edwards, Ascough, Bond, Cook, Dockrill, Dugmore, McGovern, Nesbitt & Simpson, “Vikings were not the first colonizers”, p. 231.

9. Jan Bill, “Ships and Seamanship” in Peter Sawyer (ed.), The Oxford Illustrated History of the Vikings (Oxford 1997), pp. 182-201.

10. Church, Arge, Edwards, Ascough, Bond, Cook, Dockrill, Dugmore, McGovern, Nesbitt & Simpson, “Vikings were not the first colonizers”, p. 231.


Volcanoes probably don’t explain everything

I have mirrored on my various computers a huge directory called ‘toread’, in which get stuffed willy-nilly the various PDFs of academic writing that I come across while out and about the net, and every now and then I make a short-lived assault on it. At the time of writing this had just brought me into contact with an unusual article from Speculum of 2007, in which notable medievalists Michael McCormick and Paul Edward Dutton team up with a climate scientist by the name of Paul Mayewski and ask, more or less, can we achieve anything like precision in assessing how the weather and changes in it affected the societies of the early Middle Ages?1 And this is a thing I care about, sort of, so it probably won’t surprise you to learn that I read this with a sharp eye and have an opinion about it.

The Icelandic volcano system of Eldgjá

The Icelandic volcano [Edit: system] of Eldgjá, blamed here for an eruption c. 939 on the basis of tephra analysis. “Eldgja” by Andreas TilleOwn work. Licensed under CC BY-SA 3.0 via Wikimedia Commons.

Firstly it needs to be stressed that this is not an article about climate change, per se, though there is a certain amount of that in it as background. Cautious work I’ve seen on climate change has stressed that while it deals in overall trends of up or down a degree or two, the actual experience of this would have been far less comprehensible because of a huge range of local and chronological variation. If, for example, the winter temperatures where you are range from -18° Celsius to 13° Celsius over ten years, when a century earlier it had been -13 to 18, then yes, the median drop is already pretty severe but perceiving the actual pattern in any of those ten-year slots is going to have been pretty difficult given that maybe one January all the rivers froze and then maybe four years later your vines grew a second harvest because it was so sunny.2 And this article is interested in that short-range variation, the experience of individual years.

Ice core SO4+ and Cl- time series covering the period A. D. 650–1050 and historically documented multiregional climate anomalies between 750 and 950

“Ice core SO44+ and Cl time series covering the period A.D. 650–1050 and historically documented multiregional climate anomalies between 750 and 950″, they say on p. 877

The way they take this on is relatively simple, though it must have required a lot of work: McCormick and Dutton, both of whom have pedigree in this kind of question, separately compiled lists from documents of especially extreme winters in the years 750-1000, while Mayewski pulled a huge dataset from a Greenland ice core extracted in the 1980s and went through it looking for spikes in the deposition of chemicals associated with volcanic eruptions, whose aerosol effects in blocking out sunlight and lowering temparatures the authors work hard to show are widely accepted in meteorology.3 Then they compared their findings, chucked out anything that wasn’t certain and still had nine episodes where the dates for bad winters in the documents married up closely with dates for volcanic deposits.

For me, a historian, the best parts of this article are the documentary extracts that make it clear what kind of consequences such weather could have and just how bad it could be. For example, read this, their summary of two probably-related chronicles from Constantinople about the winter of 763 to 764:4

“Some 2,000 kilometers to the southeast, a well-informed observer at Constantinople recorded that great and extremely bitter cold settled on the Byzantine Empire and the lands to the north, west… and east. The north coast of the Black Sea froze solid 100 Byzantine miles out from shore (157.4 km). The ice was reported to be 30 Byzantine ‘cubits’ deep, and people and animals could walk on it as on dry land. Drawing on the same lost written source, another contemporary, the patriarch of Constantinople, Nicephorus I, emphasized that it particularly affected the ‘hyperborean and northerly regions,’ as well as the many great rivers that lay north of the Black Sea. Twenty cubits of snow accumulated on top of the ice, making it very difficult to discern where land stopped and sea began, and the Black Sea became unnavigable. In February the ice began to break up and flow into the Bosporus, entirely blocking it. Theophanes’ account recalls how, as a child, the author (or his source’s author) went out on the ice with thirty other children and played on it and that some of his pets and other animals died. It was possible to walk all over the Bosporus around Constantinople and even cross to Asia on the ice. One huge iceberg crushed the wharf at the Acropolis, close to the tip of Constantinople’s peninsula, and another extremely large one hit the city wall, shaking it and the houses on the other side, before breaking into three large pieces; it was higher than the city walls. The terrified Constantinopolitans wondered what it could possibly portend.”

As well they might! And of course, all this matters a very great deal in a society where the principal source of wealth and indeed subsistence is agriculture. Firewood can’t be gathered, new crops can’t be planted or are blighted by the temperature, animals die, wine freezes in barrels and is ruined, famine is grimly sure to follow.5 There certainly should have been big consequences of this kind of climatic variation.

Manuscript illumination of Emperor Louis the Pious as a Roman-style 'miles christi', by Hraban Maur

Manuscript illumination of Emperor Louis the Pious as a Roman-style ‘miles christi’, by Hraban Maur, not visibly taking any responsibility for the climate. “Ludwik I Pobożny“. Licensed under Public domain via Wikimedia Commons.

The first problem, though, is that it’s very hard to determine these consequences in any consistent way. The article opens with the suggestion that the harsh winter of 763 caused King Pippin III of the Franks to suspend his campaign against Aquitaine; it very nearly closes by suggesting that the run of bad winters and harvests from 821 to 824 helped plunge the Frankish Empire into war. So hang on: are wars more or less likely when the winter’s bad? Presumably it depends on other factors. And so on. The one thing that seems pretty certain is that people would have read the bad weather as divine punishment for someone’s misdeeds, but recent work on Louis the Pious makes it more than clear that that could be seized on and used to political advantage; we just can’t agree on whose advantage it was to…6

Causation is one of the problems I have with this article, and in fact I sense that the authors did too. There are a lot of ideas put forth then qualified in the concluding section, as if one or other author was happier to hypothesize than their counterparts. They note that the Roman Empire suffered very few of these events till its closing centuries, but then immediately say, “few would maintain that volcanically caused climate anomalies determined the course of empires and civilization”. Much larger jumps out and back are visible here:7

“A child born in 765 could die at the ripe old age of fifty-five without having lived through such a winter. One born in 820 would experience five such crises in the same span. Charlemagne was more than vigorous and smart: he was, with respect to volcanic aerosols and rapid climate change, a very lucky ruler.  Not so his son Louis the Pious, who, perhaps not entirely  coincidentally, in August 822, after the terrible winter of 821–22, ostentatiously expiated before his assembled magnates his and his father’s sins. Unfortunately, his act of public  penance would have little effect on the volcanic aerosol that produced yet another terrible winter, famine, and disruption but a year later. The reigns of his sons Louis the German and Charles the Bald would suffer from three such bad climate years each; in between two of them, Louis invaded Charles’s kingdom.”

If I’d submitted that to a journal like this I’d almost have expected it to come back stamped with “CORRELATION DOES NOT EQUAL CAUSATION” and indeed, if this had gone to a science journal I feel sure this would have been redacted. “Perhaps not entirely coincidentally”? Come on… This doesn’t diminish the factuality of their observations, but it certainly does need to be carefully considered just what this data explains.

The paragraph quoted also exposes another problem with the method adopted. In terms of volcanic aerosols, yes, Charlemagne may have been lucky, but the ruler who lived through the famines of 792-793 and 806 might have been surprised to be told so.8 If volcanoes caused bad weather, they certainly didn’t cause all of it, nor even perhaps the worst of it. This is something the authors of this article willingly admit, not least because their proxy for volcanic activity is located to the west of the most likely volcanoes, in Iceland, and the area they’re studying is to the east, though the Gulf Stream makes that much less of an objection than it sounds.9 Nonetheless, when the recent ash-cloud closed the Atlantic to air travel, I personally didn’t notice any shortfall in local autumn apples in the UK, did you? And so on.

Map of volcanically-linked climate anomalies of the Frankish period with dates

Map of relevant events with dates from their p. 875

When one looks more closely at the chronology, in fact, this gets rather odder. There are acknowledged problems with the chronology here; the texts, though subjective, are at least reasonably chronologically precise, and it’s useful to see it all together, because it means that even when things with chronology as shaky as the Irish Annals are being deployed, they’re being correlated with unconnected texts that give one some confidence in the dates. Not so the ice-core, unfortunately; that was sampled every two and a half years and the possible error of each sample is somewhere between one and six years.10 When one notices, then, that the volcanic deposition evidence that correlates with the 763-4 ‘event’ came from the slice for 767, obviously that possible error is important; either the sample’s dating must be emended, or the bad weather was well in force before the volcano did its stuff. The authors seem too comfortable about this for my liking and I agree with them very much that it would be nice to get a new core with the more precise dating that is now possible.11 That would also refine cases like bad winters in 855-856 and 859-860 which correlate with deposition spikes in 854, 856 and 858. It does fit quite nicely but whether or not, as the authors prefer, this was one long volcanic event, the fact that it apparently got better in the middle again monkeys with any simple causation from volcanic eruption to economic and climatic distress. I do think this article shows that something was going on here that deserves to be considered, and I am myself still very much of the persuasion that such factors do need to be considered as explanations for social change, but despite the extra precision attempted here I still don’t think we have anything as simple as A causes B causes C here, and I don’t honestly see how we get it, however much the technology may improve.

1. Michael McCormick, Paul Edward Dutton & Paul A. Mayewski, “Volcanoes and the Climate Forcing of Carolingian Europe, A.D. 750–950” in Speculum Vol. 84 (Cambridge MA 2007), pp. 865-895.

2. There’s lots of examples of freezing rivers (and occasionally seas!) in the article; the second harvest of grapes is something that repeatedly comes up in Gregory of Tours’s Histories, though it’s never good: see Gregory of Tours, The History of the Franks, transl. Lewis Thorpe (Harmondsworth 1974, many reprints), VII.11 or IX.5.

3. McCormick’s and Dutton’s work on such matters is in fact encapsulated in the same volume, in the forms of M. McCormick, “Molecular Middle ages: early medieval economic history in the twenty-first century” and Paul Edward Dutton, “Observations on Early Medieval Weather in General, Bloody Rain in Particular”, both in Jennifer R. Davis & McCormick (edd.), The Long Morning of Medieval Europe: new directions in early medieval studies (Aldershot 2008), pp. 83-97 & 167-180 respectively. On the methodology, see McCormick, Dutton & Mayewski, “Volcanoes”, pp. 867-878 and esp. 876-878.

4. Ibid. pp. 880-881, citing “The Chronicle of Theophanes Confessor: Byzantine and Near Eastern History, A.D. 284–813, trans. Cyril A. Mango, Roger Scott, and Geoffrey Greatrex (Oxford, 1997), pp. 600–601″ and “Nikephoros, Patriarch of Constantinople, Short History 74, ed. and trans. Cyril Mango, Corpus Fontium Historiae Byzantinae 13 (Washington, D.C., 1990), pp. 144–49, here pp. 144, lines 1–16, and 147″, along with full edition refs for Theophanes and some discussion of the connection between the sources.

5. McCormick, Dutton & Mayewski, “Volcanoes”, and their refs at e. g. pp. 879 (blight), 882 (impossibility of planting), 883 (death of beasts), 885 (more blight and death of beasts, also freezing wine).

6. Ibid. p. 867 (“that surely explains the suspension of the major effort by the king to conquer Aquitaine the following summer”) cf. p. 892, quoted below; on debate over Louis the Pious see Heinrich Fichtenau, Das karolingische Imperium. Soziale und geistige Problematik eines Grossreiches (Zürich 1949), transl. Peter Munz as The Carolingian Empire (New York City 1954), Louis Halphen, Charlemagne et l’Empire Carolingien (Paris 1968), transl. as Charlemagne and the Carolingian Empire (Amsterdam 1977) or François-Louis Ganshof, “Louis the Pious reconsidered” in his The Carolingian Empire and the Frankish Monarchy (London 1971), pp. 261-272, versus the various studies in Peter Godman & Roger Collins (edd.), Charlemagne’s Heir: new perspectives on Louis the Pious (London 1990), especially Stuart Airlie’s and Janet Nelson’s.

7. McCormick, Dutton & Mayewski, “Volcanoes”, p. 892.

8. Adriaan Verhulst, The Carolingian Economy (Cambridge 2002), pp. 123-124.

9. McCormick, Dutton & Mayewski, “Volcanoes”, p. 869:

“Those same complexities mean that not every volcanic deposit in Greenland will translate directly into climate impact on the European continent, for instance, if an eruption occurred on Iceland at a moment when atypical atmospheric circulation conditions carried the aerosol westward toward Greenland.”

10. Ibid. pp. 869-870, inc. p. 869, authors’ emphasis:

“The maximum possible absolute dating error for our period in this core is approximately six years. However, within any section of the core, say 100–200 years, the relative internal error is much less, since absolute error accumulates with depth. The closer the annual layer is to a securely identified volcanic event, the more likely the error is zero.”

11. Expressed ibid. p. 891. I discovered after first drafting this a newer paper by one of the same authors and a bunch of others, Francis Ludlow, Alexander R. Stine, Paul Leahy, Enda Murphy, Paul A. Mayewski, David Taylor, James Killen, Michael G. L. Baillie, Mark Hennessy and Gerard Kiely, “Medieval Irish chronicles reveal persistent volcanic forcing of severe winter cold events, 431–1649 CE”, in Environment Research Letters Vol. 8 (Bristol 2013), pp. 24-35, doi:10.1088/1748-9326/8/2/024035, which takes the same essential data over a longer range, using however only the Irish Annals, excluding ‘unreliable’ events but not engaging at all with the difficulties of their year-by-year chronologies, and winds up essentially using those to add precision to dating of events from the same Greenland ice-core sample. I haven’t read this in detail, nor have I read much of the recent work by McCarthy on the Annals that they cite, but their approach to the texts makes me wince pre-emptively even so. Anyway, the article is Open access and can be found here, and it is picked up by the BBC here, bless them linking to the actual article unlike some, whence it was reported by via David Beard’s Archaeology in Europe where I read it, and to whom therefore a tip of the hat!


I’ll just draw it for you

This gallery contains 5 photos.

Sometimes I have no better excuse for a post than, “I found a shiny thing”, and this is definitely one of those. If I have a wider point, though, it lies in the way that the ongoing digitization of historical … Continue reading

Iberia: your genes are riding up on one side

I’ve been sitting on this paper for a while, hoping I could get some geneticist to collaborate on the write-up, because while I recognise enough of the words in genetics at least not to fall off when the argument goes round corners, I certainly can’t evaluate whether it’s soundly based or not. Simon Ford back at Clare in Cambridge gave it a once-over and thought it basically sane, though—and my thanks to him—and the point has come to write about it. Please bear in mind that I am not an expert in this stuff and would welcome any corrections or different perspectives, and read on. The work in question is a paper with twenty different authors that appeared in the American Journal of Human Genetics for 2008 entitled “The Genetic Legacy of Religious Diversity and Intolerance: Paternal Lineages of Christians, Jews, and Muslims in the Iberian Peninsula”.1 What it does is to take samples of the DNA of 1140 people from all over modern Spain and Portugal and compare them to similar datasets from Morocco and Tunisia plus an independently-derived average one for Sephardic Jews. The point of all this is the historical context that the Iberian Peninsula has, for a lot of its history, had a considerable Jewish population (`Sephardic’ actually comes from the Hebrew for Spain, ‘Sefarad’) and, of course, between about 710 and 1610, a fairly significant Muslim one that was ruling most of the area for most of that time. And, despite the fairly pompous title, what this paper does is compare what they consider to be the known history of the peninsula with the current genetic traces of population admixture.2

Haplogroup Distributions in Iberian, North African, and Sephardic Jewish Populations

"Haplogroup Distributions in Iberian, North African, and Sephardic Jewish Populations." "Sectors in pie charts are colored according to haplogroup in the schematic tree to the right, and sector areas are proportional to haplogroup frequency."

And these are, in a sense, the results. You have to realise, before you start to read this thing, that we are in a game not of certainties or clear causation here but rather of statistically significant correlation. So, you will notice that the three African samples (which they got from elsewhere3) are dominated by haplogroup E3b2 (and I’m not even going to try and explain what a haplogroup is; I would just have to copy it from a better explanation like this one anyway) but the Iberian ones are dominated instead by various branches of R1. This doesn’t stop each of those groups having some trace of the other one’s dominant element, because these things occur throughout most of humanity by now, and the question is not usually down to a single genetic signature like the ‘Cohen gene’ but to a pattern being convincingly like another pattern. If you compare it to the Sephardic Jewish signature at top right (again, from elsewhere, on this occasion a separate survey by two of the authors whose data is only given as supplemental information online4) you’ll see that there the significant marker seems to be the balance of groups G, J2 and all other J groups, which is a bit harder to spot. So, rather than just try and spot colour matches it seems worthwhile to say what the paper’s authors think they’ve found, given that they have crunched this data in a number of other ways that don’t make such colourful images, and then remark on that. Their conclusions were, roughly:

  1. Obviously, the Gibraltar Straits do mark a genuine divide in the make-up of the populations, which is not to say that there’s no common blood (ultimately, after all, we’re all cousins) but that there is a statistically significant (and fairly obvious) difference.
  2. The Basque country and Gascony have a strong showing from haplogroups that barely show up elsewhere (R1b3f, otherwise only strongly represented in Catalonia and the Balearics, weirdly; R1b3d; and in the Basque Country proper, R1b3b, which actually doesn’t show up anywhere else on the plot except for a sliver in North-West Castile, although I wonder if the big sample size there might not be something to do with that) and are also statistically quite different because of that.
  3. In the peninsula overall, admixture from an African-type parental population appears to be 10·6%, but this varies widely; there is none in the Basque zones, but 21·6% in Castile, i. e. twice as much as elsewhere.
  4. Admixture from a Jewish-type population is rather higher, 19·8% overall, but again with variation: none at all in Minorca, but 36·3% in Southern Portugal.
  5. The diversity of haplogroups within the dominant one from Africa is lower in the Iberian Peninsula than in Africa, suggesting that only a subset of the African population as it now is is represented in the peninsula’s genes.
  6. Contrariwise, the diversity of the Jewish sample in the Iberian population is higher, suggesting a longer-term admixture (though see below).
  7. The African sample is represented, not as one might expect most strongly in the south around Granada and least strongly in the north, but rather in the west, especially Castile and Galicia, that is the furthest parts north of the west, as well as also in Minorca which is less surprising maybe.5

Some of this makes perfectly good sense with what we know of the demographic history of this area, although it does persistently have to be borne in mind that we are talking about a history covering all of the last, say, three thousand years, piled up and indistinguishable. There is some possibility of distinguishing chronology with such evidence: as the authors say, the low diversity of the African sample in the Iberian peninsula compared to the Jewish or African-local ones suggests that it arrived more recently than the others because it has presumably had less time to spread and average out. But this is not ‘proving’ the Muslim conquest from genetics or anything; it is noticing a particular phenomenon that the conquest we already knew about provides an obvious explanation for. Likewise, the strong Jewish signal in South Portugal is odd until you consider that Portugal, unlike Castile or Aragon-Catalonia, didn’t expel its Jews and therefore picked up quite a lot of exile population from the reconquered areas of those two kingdoms, i. e. the south, in the fifteenth century, who have presumably left some trace in the genepool since then. On the other hand, the western-side bias of the African signal is very strange. It is certainly true that Muslim settlement, for most historians at least, is unlikely to have been substantial outside of Córdoba’s immediate zone of control, and we can do quite a lot about suggesting from place-names which groups wound up where.6 That would explain the low signal in Catalonia, but it patently conflicts with the high signal in Galicia. The authors suggest that this is down to the forced relocation of the morisco populations to the north and west after the war of 1567-71,7 and so indeed it may be—we have to watch that we don’t immediately conclude “OMG settlement in 711!” from this data given that it also includes all movements since—but if so it seems very strange to me that the areas where we know Muslims were for longest show less of a trace, and that suggests that the incomers were distinctive and also didn’t mix very much, whereas the moriscos blended into the wider population much more.

Horseshoe arches in the Leonese church of Santiago de Peñalba

Horseshoe arches in the Leonese church of Santiago de Peñalba, another kind of evidence for cultural admixture, more or less contraindicated by the genetic evidence

There are also three problems with their conceptual framework that I see which I think need discussion. The first, they have anticipated and headed off, although they don’t phrase it quite as I would, which is that if this Jewish signal prototype they have is already based on Jews from only this area then inevitably, you’d think, it is going to be much more admixed with Iberian material than a sample of a population outside Spain. In other words, there is a risk here of concluding, “Iberian Jews… are quite Iberian“, what is somewhat less exciting than the assertion “Iberian populations surprisingly Jewish”, which is more like what the paper actually says. The authors were not worried about this, as far as I can tell, but were concerned that the self-identification of the Jewish population that was used to obtain the sample on which they relied, i. e. the DNA of people who think they’re Jewish by descent, might well be less exclusively Jewish than those people thought. The counter that they have to this also works for my worry, however, it being that there are within that Jewish sample, as well as quite a lot of haplotypes shared with Iberian populations, three or four that are not but do match strongly with the Middle East. So, as long as they aren’t Greek or Phœnician (the long time-frame again), which seems unlikely given that they are as strongly visible in the West as the East, that does show some genuine Semitic ancestry to the sample group.

Iberian, North African, and Sephardic Jewish Admixture Proportions among Iberian Peninsula Samples

"Mean North African, Sephardic Jewish, and Iberian admixture proportions among Iberian samples, based on the mY estimator and on Moroccan, Sephardic Jewish, and Basque parental populations, are represented on a map as shaded bars on bar charts. Error bars indicate standard deviations, and three-letter codes indicate populations, as given in Figure 1."

That takes us straight to the second problem, though, which is one of missing populations. I am broadly happy that most of the Muslim army of 711 and subsequent settlement was probably composed of Berbers and other Africans (even if allegedly some of them might have been Vandals by descent…), I think this is one of the things that Guichard’s work makes acceptable, but nonetheless they weren’t all Berbers, there was an actually-Arabic presence in the officer corps, because we know some of them by name, and of course there was also a massive civil war in 741 kicked off, as the chronicles of the time (at least, compared to the chronology of the genetic evidence) see it, by a fresh wave of settlement direct from Syria.8 So it seems to me that when we see a Middle Eastern genetic sample, it doesn’t have to be Jewish, and that ideally there would be some way to check this sample for what might be a tiny tiny Arabic representation, but might not (and it would be really nice to know which and where).

The bronze inscription of Botorrita, in eastern Ibero-Celtic characters

The bronze inscription of Botorrita, in eastern Ibero-Celtic characters

Then there is another missing population, which is the actual Iberians. Quite early on the authors decide that the best comparator for the African and Jewish samples is the Basque one, as it shows no or little mixture with those groups, so everything else in the peninsula is then thought of as being more or less of a mixture between the three `parental’ samples. Well, OK, but whenever the Basques arrived in Spain, other groups followed, most obviously the Celtic groups we now call Iberians, and also maybe some Visigoths, you know, though we don’t seem to credit that those were numerically significant any more.9 I don’t think it diminishes the significance of the African and Jewish samples being different in the ways that they are too much, but I think that a better conceptual model might have been instead to take a total average of the peninsula and emphasise differences from it globally, rather than thinking in terms of `amibasqueornot’. Or, again, perhaps it would just be nice to have had some potential Celtic (or even Gothic) comparators factored in too so that we might get some sense of where those groups might have been best preserved, if they are at all. The paper’s only 11 pages long, after all, though I realise that I may just have idly asked for about three or four more years’ computing and sampling.

Interior of Santa María la Blanca, Toledo, previously a synagogue built in Almohad style

Interior of Santa María la Blanca, Toledo, previously a synagogue built in Almohad (i. e. a Berber Muslim) style. From Wikimedia Commons

So, in short, this stuff is really interesting but it’s very difficult to distill it down to historical events without essentially using what we already know to explain this new data. I get a certain kick out of knowing that some of the more traditional Reconquista-minded scholars would have been horrified to think that heroic Castile was actually more African and more Jewish than other areas of the peninsula but, if that’s down to post-reconquest resettlement by the kings, that becomes less of a delicious irony and more likely to be a reflection of the fact that populations who feel their identity may be dissipating are more likely to stress it aggressively. I think that these samples could actually be interrogated to tell us more about the settlement period by, for example, adding Arabic and Celtic comparators (if the latter can really be assembled, given how vague a group `Celtic’ populations are when considered historically10). At the moment, though, the main early medieval takeaway from this, which is what I at least am really interested in, is that it looks to be demonstrable that the African settler groups who (probably) arrived with and after the Muslim conquest really didn’t mix very much with the local populations. That’s not nothing, but I would still like to know if we might some day be able to guess at how much of the settling population they were from this kind of data, and thus guess also at the change in the élite too.

1. Susan M. Adams, Elena Bosch, Patricia L. Balaresque, Stéphane J. Ballereau, Andrew C. Lee, Eduardo Arroyo, Ana M. López-Parra, Mercedes Aler, Marina S. Gisbert Grifo, Maria Brion, Angel Carracedo, João Lavinha, Begoña Martínez-Jarreta, Lluis Quintana-Murci, Antònia Picornell, Misericordia Ramon, Karl Skorecki, Doron M. Behar, Francesc Calafell and Mark A. Jobling, “The Genetic Legacy of Religious Diversity and Intolerance: Paternal Lineages of Christians, Jews, and Muslims in the Iberian Peninsula” in The American Journal of Human Genetics Vol. 83 (Bethesda 2008), pp. 725-736, DOI 10.1016/j.ajhg.2008.11.007 (open access). Twenty authors seems like enough, really, although I can’t help feeling that they could also have credited the historian they consulted with (see below) and, after all, this is very far from the most extreme case of multiple authorship I can think of.

2. For the known history, they appealed to Dolors Bramon (ibid. p. 734, Acknowledgements), who is the current expert on what is to be learnt about Christian Iberian history from Islamic sources; her little anthology, De Quan Erem o No Musulmans: Textos del 713 al 1010. Continuació de l’Obra de J. M. Millàs i Vallicrosa (Vic 2000), is a frequent source of great help to me. So that was an unusually good choice, really, but apparently not a research contribution. Hmph.

3. Adams et al., “Genetic Legacy”, p. 727, citing E. Bosch, F. Calafell, D. Comas, P. J. Oefner, P. A. Underhill and J. Bertranpetit, “High-resolution analysis of human Y-chromosome variation shows a sharp discontinuity and limited gene flow between Northwestern Africa and the Iberian Peninsula” in American Journal of Human Genetics Vol. 68 (Bethesda 2001), pp. 1019–1029, and B. Arredi, E. S. Poloni, S. Paracchini, T. Zerjal, D. M. Fathallah, M. Makrelouf, V. L. Pascali, A. Novelletto and C. Tyler-Smith, “A predominantly neolithic origin for Y-chromosomal DNA variation in North Africa”, ibid. Vol. 75 (2004), pp. 338–345.

4. Adams et al., “Genetic Legacy”, p. 727 and describing work by Doron M. Behar and Karl Skorecki; the data is tabulated in the online version of the paper as “Haplogroups and Y-STR Haplotypes of Iberian Peninsula and Sephardic Jewish Samples” here (PDF).

5. Here as elsewhere, the sample from Asturias is just too small to allow significant conclusions, which may be just as well considering how much that one would expect is missing from it. This gives me pause, again, about drawing conclusions too far from the other areas with proportionally lower representation in the samples, including not least Minorca of course.

6. For the somewhat localised nature of the Andalusi state, I am used to citing Eduardo Manzano Moreno, La frontera de al-Andalus en la época de los Omeyas, Bibliotheca de Historia 9 (Madrid 1991), though I had the great pleasure of meeting the author this week and he tells me that he would now revise most of it! Extremely frustrating, as I have come to see it as canonical, which may be exactly why he would like to change it. Anyway. For place-names and settlement, the work of resort is by Pierre Guichard, either in French as Structures sociales « orientales » et « occidentales » dans l’Espagne musulmane (Paris 1977) or trans. into Castilian & rev. as Al-Andalus. Estructura antropológica de una sociedad islámica en Occidente (Granada 1998), though Dr Manzano tells me this too must be considered obsolete now. I don’t know if I’d agree there (or, it turns out, with quite a lot else Dr Manzano would argue, which was fun; more on this in due course). Compare Jessica A. Coope, “Marriage, Kinship, and Islamic Law in Al-Andalus: Reflections on Pierre Guichard’s Al-Ándalus” in al-Masaq Vol. 20 (London 2008), pp. 161-177, which is interesting because it disagrees with Guichard in exactly the opposite direction to Dr Manzano. For an English introduction to these issues, albeit a controversial one, see Roger Collins, The Arab Conquest of Spain, 710-797, History of Spain 4 (Oxford 1989). Collins caught it from the critics here because he effectively refuses to use Arabic historical writing, reckoning it all far too late and legendary to be anything other than misleading. There is also, of course, the fact that he doesn’t read Arabic, and this makes him an easy critical target because of course how can he know what he’s missing? but if you compare the exactly contemporary and much more traditional ‘Abdul Wahid Dhanun Taha, The Muslim Conquest and Settlement of North Africa and Spain (London 1989), I would say that it is fairly clear that Collins had a point. The fact that we can get three books like Collins, Taha and Guichard all purportedly telling the same story and disagreeing so incredibly (to say nothing of Manzano’s Frontera) is a measure of how charged these debates are. Without that charge, after all, how could we ever have had the now-legendary Ignacio Olagué, Les Arabes n’ont jamais envahi l’Espagne (Paris 1960, 2nd edn. 1973), to which cf. Pierre Guichard, “Les Arabes ont bien envahi l’Espagne : les structures sociales de l’Espagne musulmane” in Annales : Économies, sociétés, civilisations Vol. 29 (Paris 1974), pp. 1483-1513. I may have become sidetracked here.

7. Adams et al., “Genetic Legacy”, pp. 732-733.

8. Testified to even in the Christian Chronicle of 754, also known as The Mozarabic Chronicle though `Mozarab’ is one of those words that means too many things and should be retired, as translated in Kenneth Baxter Wolf, Conquerors and Chroniclers of Early Medieval Spain, Translated Texts for Historians 9 (Liverpool 1990, 2nd edn. 1999), pp. 111-160 with commentary pp. 25-42, cc. 82-86 in which the chronicler helpfully tells us that he wrote a whole book about this already so won’t repeat himself here. Do we have the book? No, we do not. Ah well. Nonetheless, it is this proximity to events that caused Collins to favour Christian sources over the Arabic ones. On the difficulties with the term `Mozarab’, see Richard Hitchcoock, Mozarabs in Medieval and Early Modern Spain: identities and influences (Aldershot 2008), passim but esp. pp ix-xx.

9. Roger Collins, Visigothic Spain 409-711, History of Spain 3 (Oxford 2004), pp. 25-26.

10. On which you can see the brief and bracing statements of Guy Halsall, who risks Godwin’s Law at an early stage of a book by comparing Celticism to Germanism in his Barbarian Migrations and the Roman West, 376-568, Cambridge Medieval Textbooks (Cambridge 2007), pp. 24-25.

‘Iron Age’ Picts and their spoken language

Okay, here’s another thing I wanted to write up before I went to Kalamazoo. You may have seen, if you are following Archaeology in Europe as you all should be, that there was a recent paper in Proceedings of the Royal Society A that apparently decodes the Pictish language or something similar. I confess to initial scepticism, not least because they inexplicably persist in using the term `Iron Age’ for a people only attested under the name ‘Picts’ from the Roman period onwards, and whose glory days are most definitely early medieval, but I am interested in the Picts, I am in favour of Science! in history and so I thought I’d better have a look. After all, I am developing a blog-tradition of critiquing scientific papers on matters historical, and I’d hate to pass up another opportunity. Now, if those instances have taught me anything, it is these things:

  1. articles based on the press release usually massively exaggerate the impact, and indeed the intent, of the actual research;
  2. the actual research is usually more interested in proving a method than in its applications, otherwise it would have been published in a historical forum not a scientific one; and,
  3. it is unfortunately rare for the authors of that research to have read enough in the field to which they’re supposedly contributing to have an accurate sense of whether or not they really are.

And this particular case ticks all three boxes, which is to say it’s interesting, appears scientifically rigorous at first glance, but sadly isn’t going to add much to the historical or linguistic debates, even though the news coverage would have you believe it’s a revolution in the field. So first of all I’ll deal with what the paper is doing, then try very briefly to describe the debate in which it belongs, and lastly assess the former against the latter. And because these things turn out to take a while, I will do so behind a cut… Continue reading

Book bit bullets I

Because sometimes you only have a sentence worth of content and it seems foolish to make them all their own posts.

  • One that probably will be a separate post, if I can find the images, but it’s too late in the day now: Jerrilyn Dodds is clearly very clever and has reminded me in an impressively subtle and persuasive article that architecture genuinely can be an important window, no pun intended, on ideology.1
  • Jonathan Phillips‘s book about the Latin kingdoms of the Holy Land and their links to the west, though it does go through some background details too thickly and/or several times over, is still a really intriguing account of the East itself in that era, tying together a number of strands that would otherwise probably get left out of an ordinary history of the Latin settlements.2
  • Lastly, radio-carbon dating has its problems because of the need to calibrate, as we know, but even as I’ve been drafting this post scientists have been on the case and the calibration curve considerably refined, as you may have seen. This makes it downright contrary of me to have just caught up with a five-year-old paper arguing that, even when advances of this sort are made, what they reveal is not greater precision in dating, but that there are problems inherent in the samples we use to date stuff in the first place that possibly make precision tighter than currently available impossible anyway!3

Oh well, that’s all for this one…

1. J. Dodds, “Entre Roma y el Romànico: el mito de Occidente” in Jordi Camps (ed.), Cataluña en la época carolingia: Arte y cultura antes del románico (siglos IX y X) (Barcelona 1999), pp. 147-155, transl. as “Between Rome and Romanesque: the myth of the west” ibid., pp. 492-496.

2. J. Phillips, Defenders of the Holy Land: relations between the Latin East and the West, 1119-1187 (Oxford 1996).

3. A. Bayliss, E. Shepherd Popescu, N. Beavan-Athfield, C. Bronk Ramsey, G. T. Cooke, A. Locker, “The potential significance of dietary offsets for the interpretation of radiocarbon dates: an archaeologically significant example from medieval Norwich” in Journal of Archaeological Science Vol. 31 (Amsterdam 2004), pp. 563–575.

Bad history done better

Still short on time to generate actual content here, I hope you’ll forgive a second post in a row instead directing you to look at something else; it is good, I assure you. You are, I hope, aware of a column in the UK’s Guardian newspaper by Dr Ben Goldacre called Bad Science, in which he more or less single-handedly tries to take on misunderstanding and misrepresentation of the natural sciences, especially medicine, drugs and clinical trialing, in the media and advertising. (Aha! He is also posting it as a blog. So blogrolled.) It’s a valuable and under-rewarded service, because really I would like there to be a publicly-funded blog or website doing this, a kind of scientific Snopes.com debunking that which needs debunking,* to which people could go and get the, er, straight dope.

Now every now and then I’ve been part of conversations among historians in which someone has said, “We should,” or even, “You should,” with my copious free time no doubt, “start a Bad History site to do the same thing when someone talks rubbish about our stuff!” And well, you know, we do what we can. But, I’m very happy to say (and to thank Bavardess for writing the post by which I learnt it) that rival newspaper The Times has in fact stepped up to this mark with a piece in its Higher Education Supplement by Matthew Reisz, who lately proved so helpful to Terence Kealy in making an ass of himself, in which he gets numerous historians, including some medievalists, to pick a particular mistake they’d like to correct and to ‘get medieval’ on it.** It’s good. Go have a look, and encourage them to do another. Then, if you like (and you should) go have a look at this commentary by Gesta at On Boundaries, who is equally pleased by this turn of events. And meanwhile I must contact Dr Goldacre and see if we can put together a funding bid for the UK Office For Correcting Mistaken Claptrap…

* Hey, Latin? Can I borrow some gerundives of obligation? Yours are so much nicer than ours.

** Yes, that’s right, they assemble a huge council, debate on it in two chambers, one for the laymen and one for the ecclesiastics, submit their findings to the presiding ruler and he issues a proclamation banning all such work from the kingdom.***

*** No, okay, what really happens is, they organise the opening of an IKEA store and then stampede people to death at its doors.****

**** Look, seriously, by now you could have found out the truth for yourself, and Dr Pyrdum wants his footnote style back so I can’t tell you any more.