Tag Archives: Persia

All That Glitters, Phase 4

The times continue strange in UK higher education, as you may have seen. Many of us are on strike for what is now the third week, more of us than ever now, and the employers’ representatives appear to be refusing to negotiate in person and then changing their mind by Twitter overnight. I don’t know what may happen in the next 48 hours and of course in case classes happen, they all have got to be got ready on the few days when we’re not on strike, in case something is resolved that means we go back to work. But, what this does mean is that my conscience is pretty clear about blogging. Having taken my first steps down a new road in the previous post, it thus behoves me to look around myself and say, ‘What was I doing in July to September 2015 that I haven’t already told you about?’, and the answer to that is not limited to but certainly includes, ‘zapping gold coins with X-rays some more’. So this is about our fourth set of tests.

Jonathan Jarrett and a gold solidus with XRF machinery in the Department of Chemistry, University of Birmingham

Posed, obviously; I may look intrepid, but you have no idea how tightly I was holding that coin. It rolling under the machine would have spoiled several people’s day quite badly…

If you remember, where we were with this is that having got money to evaluate techniques by which we might be able to use X-ray fluorescence spectroscopy to measure the metal content of Byantine coins, with an especial eye on trace elements that might betray metal sources, we had fairly quickly established that the kind of portable machinery which we could bring to the coins in their museum wouldn’t tell us what we needed to know. So the working set-up for these experiments was now that, after having checked our insurance quite carefully, as soon as I could get into the Barber’s coin room of a morning I would remove from it about 100 g of high-purity gold in the form of 20-odd Byzantine and other coins, then University security would turn up (in theory) and transport me to the School of Chemistry (in theory). We would then do as much zapping as could be done, with at least two people present where the coins were at all times, before Security turned up again (in theory) in time to get me and the coins back into the Barber before it closed. And this time we did this for four days running. I won’t tell you how many ways this process could go wrong, but I haven’t flagged them all. But Chemistry were lovely and very generous both with expertise and with biscuits, and though we never had quite the same team there two days together it was all quite a good group exercise anyway. So, what were we doing this time and how did it go? The answer is a long one, so I’ll put it behind a cut, but do read on! Continue reading


All That Glitters, Experiment 1

Almost the last academic thing I did last year before breaking for Christmas was the first two sessions of a project that is now nearly finished, All That Glitters, announced here so long ago. It was so long ago that it might be worth reintroducing. Basically, by great happenstance one of my predecessors in taking care of the coin collection at the Barber Institute had run into two people at a conference who were presenting about the ability of the X-ray fluorescence (XRF) equipment their company, Bruker Industries Ltd., produced to do metal analyses. That predecessor, Rebecca Darley, also knew Robert Bracey at the British Museum, who had done work with XRF on the coinage of the Kushan Empire, and now I was in charge of the Barber’s coins. None of us are archæometallurgists and our knowledge of archæology and numismatics didn’t necessarily combine with the metals analysis expertise upon which we could call so as to somehow make a composite archæometallurgist out of us all, but Robert could borrow the British Museum’s handheld XRF scanner, Bruker had a new machine they wanted to test against real problems, the Barber is on the same campus as several much larger and more expensive machines also supplied by Bruker some of whose host departments proved happy to let us use them and to tell us about them; a project seemed obviously to exist in potentio and our task was to work out how to make it tell us something useful.

Bruker Industries Tracer IV handheld XRF analysis system

I’m not sure if this is the exact machine we were using but its resemblance to a phaser seems impressively reminiscent

It’s too early to say whether we achieved that, pending actual publication of our results and conclusions which we are even now working on writing up, but right from the beginning it was clear to us that before we could have any historical conclusions we would have to have methodological ones. This is because there are so many potential problems with XRF analysis, problems which not all publications using it consider, and when they do, consider most often for silver alloys rather than the high-purity gold we would be testing, that the first priority had to be not to find things out, but rather to find out what we could find out.1 Accordingly, our pilot experiments were designed to evaluate the machinery more than the coinage, and we started on the 3rd December 2014 when Robert brought the British Museum’s handheld scanner up from the British Museum, along with its calibration standard, and Mike Dobby and Colin Slater from Bruker brought in their new M1ORA energy-dispersive scanner and we put some coins through their x-rays.

A gold solidus of Emperor Anastasius I struck at Constantinople (in the Eta <i>officina</i>) between 492 and 507, Barber Institute of Fine Arts B0005

The first coin to go under, a gold solidus of Emperor Anastasius I struck at Constantinople (in the Eta officina) between 492 and 507, Barber Institute of Fine Arts B0005

We had chosen a test set of ten coins running from Anastasius I (491-518) to Constantine VI (785-797), with two coins for each ruler from the same mint and if possible, the same workshop of the mint (if that’s what officinae were), hoping that whatever results we might obtain would thus be internally secure against outlier coins from a bad day at the mint or similar.2 All of those got zapped on both sides with both handheld and the microwave-like M1ORA. Both of these use a spot beam, but with the M1ORA it’s possible to target it precisely, so we aimed for flat surfaces wherever possible.

Bruker Industries M1ORA XRF analyser at work in the Coin Study Room of the Barber Institute of Fine Arts, University of Birmingham

The M1ORA at work in the Barber’s Coin Study Room, with team members in eager attendance

The initial results of this made the handheld device look like much the poorer sibling, as its readings were extremely variable. Robert worked out, however, that this was related to how much of its expected sample it had been able to observe—this in turn probably down to surface relief but already we were into unknowns—and when the figures were all normalised to a notional 100% of sample they came out much more like what the M1ORA was seeing. The M1ORA was able to dump its readings straight into a laptop equipped with suitable software, and did this levelling-up in that software, so made things immediately clearer for us by automating that step, solely an issue of configuration but we still needed to be aware of it. I keep stressing variables and difficulties because I don’t want to imply that we were getting actual true results, but that said, once they were both talking to us in the same framework the message of the machines was pretty consistent: all these coins were being analysed as very high-purity gold, 97% or more, which is astonishingly high for any pre-modern metallurgy. However, other than silver and copper, which occurred in about the proportions one would expect (i. e. not very much and even less), the only other element that was consistently detectable was iron. That was in part a factor of what we had asked Mike and Colin to make the machinery look for but if you have to do that at all, there is obviously a restriction inherent in your question-setting…

A gold dinar of Sindh imitating a Persian dinar of Shah Shapur II (309-379), struck at an unknown mint and date, Barber Institute of Fine Arts S0073

So then for something rather different, a gold dinar of Sindh imitating a Persian dinar of Shah Shapur II (309-379), struck at an unknown mint and date, Barber Institute of Fine Arts S0073

The very high fineness was sort of what we might have expected, anyway, as it is roughly what earlier analyses of Byzantine gold coins by a number of methods have suggested.3 It still made me uncomfortable for its lack of variety, however, and so since we had run-time left in the day I started hauling other things out of the cabinets. These included two Persian gold dinars, of Shahs Shapur II (309-379) and Varhran IV (388-399), and the above piece which is pretending to be something like the former, as well as an Arab-Byzantine solidus from Carthage and some more Byzantine pieces. Mainly I just wanted to be sure that the machinery actually would report lower gold finenesses, and so it duly did, with the Persian pieces both lower (but not by the same amount) and the Sindh piece even less fine (which, to be honest, was already apparent in its colour, but that was why I’d chosen it). The Byzantine stuff, and the coins imitating that, remained high in the machinery’s estimation.

A gold solidus of the second reign of Emperor Justinian II, struck at Constantinople between 705 and 711, Barber Institute of Fine Arts B4464

Another part of the starting sample, a gold solidus of the second reign of Emperor Justinian II, struck at Constantinople between 705 and 711, Barber Institute of Fine Arts B4464

This bit was fairly unsystematic sampling, but it did give us some reason to believe that the machinery was observing something consistent with our expectations, and which therefore fitted into existing understandings of the early Byzantine gold coinage. That is circular, though, obviously! This and the likely effect on the readings of differences between the surface of the coins and their cores, because of both manufacturing factors and subsequent environmental exposure, meant that we weren’t willing (and still aren’t) to say that these figures are actually how fine those coins were. We also weren’t seeing a range of trace elements which we had expected on the basis of older work, and which might have suggested things about changes in metal supply and treatment that would potentially be historical evidence.4 So, while these machines might serve other people’s purposes, we ourselves were going to need some bigger kit. And that would be Experiment 2, about which I shall write in a couple of posts’ time. In the meantime, however, here is some shiny metallic blogging for the Christmas season and I wish you all a happy holiday!

1. Part of our problem was that so much of the literature about these problems was old enough to relate, potentially, only to a much more primitive incarnation of the technique. Nonetheless, Michael F. Hendy & J. A. Charles, “The Production Techniques, Silver Content and Circulation History of the Twelfth-Century Byzantine Silver Trachy” in Archaeometry Vol. 12 (Oxford 1970), pp. 13-21, William A. Oddy, “The Analysis of Gold Coins—A Comparison of Results Obtained by Non-Destructive Methods”, ibid. Vol. 14 (1972), pp. 109-117 and J. Tate, “Some Problems in Analysing Museum Material by Nondestructive Surface Sensitive Techniques” in Nuclear Instruments and Methods in Physics Research Part B Vol. 14 (Amsterdam 1986), pp. 20-23, all suggest that differences should be observable between surfaces and cores of coins and between methods that measure only the surface and those that measure total composition, and L. Beck, S. Bosonnet, S. Réveillon, D. Eliot & F. Pilon, “Silver surface enrichment of silver–copper alloys: a limitation for the analysis of ancient silver coins by surface techniques”, ibid. Part B Vol. 226 (2004), pp. 153-162, DOI: 10.1016/j.nimb.2004.06.044 and Vasiliki Kantarelou, Francisco José Ager, Despoina Eugenidou, Francisca Chaves, Alexandros Andreou, Elena Kontou, Niki Katsikosta, Miguel Angel Respaldiza, Patrizia Serafin, Dimosthenis Sokaras, Charalambos Zarkadas, Kyriaki Polikreti & Andreas Germanos Karydas, “X-ray Fluorescence analytical criteria to assess the fineness of ancient silver coins: application on Ptolemaic coinage” in Spectrochimica Acta Part B Vol. 66 (Amsterdam 2011), pp. 681-690, DOI: 10.1016/j.sab.2011.08.001, give some explanations of why that should be so. (I have to thank Dr Eleanor Blakelock for some of these and several other useful references.) All of these except Oddy and Tate were working with silver alloyed with base metal, however, and so another of the problems we have is in knowing how far the same applies to gold and if it does, whether if alloyed with base metals only or also with noble metals such as we expected to see. And the mess only gets worse from there…

2. Barber Institute of Fine Arts B0005 & B0006 (Anastasius I, Constantinople, officinae Eta and Iota), B2761 & B2762 (Heraclius, Constantinople, both officina Eta), B4384 & B4385 (first reign of Justinian II, Constantinople, former marked Theta), B4464 & B4465 (second reign of Justinian II, Constantinople, no control marks), B4598 & B4599 (Constantine VI and Eirini, Constantinople, no control marks).

3. Those earlier analyses being principally those gathered and conducted in Cécile Morrisson, Jean-Noël Barrandon & Jacques Poirier, “La monnaie d’or byzantine à Constantinople : purification et modes d’altérations (491-1354)” in Morrisson, Claude Brenot, Jean-Pierre Callu, Barrandon, Poirier & Robert Halleux, L’or monnayé I : purification et altérations de Rome à Byzance, Cahiers Ernest Babelon 2 (Paris 1985), pp. 113-187.

4. The kind of conclusions, indeed, that were coming out of ibid. and another study there, Jean-Pierre Callu, Claude Brenot, Jean-Noël Barrandon and Jacques Poirier, ‘”Aureus obryziacus”‘, ibid. pp. 81-111, albeit with a rather more variable sample of evidence!

The power of coincidence

[This post was written on 18th November 2014 and queued; I’m finally up to it in the queue and have updated very slightly for my current situation.]

Chinese pottery at the top of the yet-to-be-excavated Belitung shipwreck in 1998

Chinese pottery at the top of the yet-to-be-excavated Belitung shipwreck in 1998

Humans are pattern-spotting animals, of course, and a great many false findings rest on our attempting to find reproducibility and significance in patterns that are effectively random. As we know, if someone is asking you in print, “Is it a coincidence that… ?” then the answer is probably yes. All the same, sometimes you cannot help but wonder. Four days before writing the first draft of this post I was at a paper where I met the word ‘keelson‘ for the first time (it’s a stiffener one puts inside a boat’s hull to support the keel on the outside, as the speaker explained).1 On the day I wrote the post I then met it for the second time, with no explanation, in the article from my to-read directory of PDFs that I have been assembling since 2008, but of course now I knew what it meant.

This particular file wound up in that directory in 2009 but I came to it only now, in November 2014, without any selection except that of when I put the file there and my ignoring a section of a thesis on Girona cathedral which I’m not sure why I wanted. So there was no reason at all for the article at the top of the heap either to mention keelsons or to be about Persian and Indian contact with T’ang China, which I was then teaching, but nonetheless it was, even though I’d grabbed the file to read five years before, when I was still working at the Fitzwilliam Museum and never expected to teach China and the Silk Routes at all.2 Don’t you also find that this kind of thing happens quite a lot? This is why I try not to mess with my routines for working through undirected reading; it often turns out to have a direction I never expected after all…

1. Rebecca Ingram, “Making it Last: the construction and repair of a 7th-century ship from Constantinople’s Theodosian harbour”, paper presented to the General Seminar of the Centre for Byzantine, Ottoman and Modern Greek Studies, University of Birmingham, 13th November 2014.

2. Michael Flecker, “A ninth-century AD Arab or Indian shipwreck in Indonesia: first evidence for direct trade with China” in World Archaeology 32 (London 2001), pp. 335-354, DOI: 10.1080/00438240120048662.

Seminar CLXXI: Türks and Byzantine strategy

Returning now to my seminar backlog, I find myself reliving my last term in employment at Oxford, and fittingly in many ways, it more or less opened with a paper by Dr Mark Whittow, Byzantinist and generalist both and a man whom I think can cope with being described as a ‘good egg’ and who had on 22nd April 2013 taken convenor’s privilege at the Medieval History Seminar to present a paper called “Worlds in Motion: Byzantium’s Eurasian Policy in the Age of the Türk Empire, 550-630”.

Mark’s essential question was whether the Byzantine state of his period had anything that could be described as a foreign policy towards the area north and east of its great enemy, Persia, and he knew his audience well enough to know that this would mean setting out in some detail what actually happened in the area and, for example, why we were talking about Türks with a diaresis. Specifically, in fact, we were talking about the Gök Türks, a supposedly-ethnic group who emerged as a political quantity in the mid-sixth century in what is now Mongolia as subjects of the Avars (something we know largely from Chinese sources) but in 552 blew up and occupied the Eastern steppes, in 556 destroying the rule of the Hepthalites or White Huns in cooperation with Persia and beginning to move in on trade along the incipient Silk Roads in Sogdia. The Persian link didn’t serve them well, however, and in 568 their western ruler made an approach to the Byzantine Emperor Justin II, leading to a joint attack on Persia in 573 that however went very badly, so that the Türks then gave up on Byzantium and in fact nicked the Crimea off it. (I have to admit, I had not known till this point that Byzantium had ever held the Crimea. I have a lot to learn.)

Sixth-to-eighth-century petroglyphs supposedly showing Gök Türks

This is the best Wikimedia Commons can do me for pictures of Gök Türks, pictures in stone from Mongolia dated to between the sixth and eighth centuries, which is at least about right for our purposes. All the same, I don’t feel this illustrates much…

This was the beginning of the end for a Türk empire that had for a while stretched from Mongolia to Iran. In 581 Persia and China managed to put together simultaneous campaigns that broke up the Türks’ eastern Qaghanate, leaving only the western one. It was however to this that a desperate Emperor Heraclius, he of beards but not badgers as I think we have shown, turned in 624 when no other expedient against the lately-triumphant Persia seemed available. the Türks had already raided Persia in 618, and no other help was to be had, so in 626 Heraclius began attacking Persia from the east, rather than the west, and next year the Türks joined in. (This we have from Nikephoros.) Exactly what contribution this made to the emperor’s following victory and the Persian collapse of 628 is probably still to be worked out but the Türks descended into civil war the next year and that is about the last we see of the Gök Türks as an autonomous polity.

A Byzantine silver plate showing David confronting his brother Eliab, thought to have been made in celebration of Heraclius's victory over Persia, now in the Metropolitan Museum of Art

A Byzantine silver plate showing David confronting his brother Eliab, thought to have been made in celebration of Heraclius’s victory over Persia, now in the Metropolitan Museum of Art but found on Wikimedia Commons

Can all this be counted as a policy, then, asked Mark? Well, in some senses no: it’s not a policy for Eurasia in the way that China had a policy for the steppes, a continuous attempt to consider them as part of their total strategic picture. What it could be seen as is a continuation of attempts to use groups from this area as an outside threat to the Persians, a diplomatic outflanking manœuvre, like the Huns and before them the Sarmatians, the Hephthalites, the Avars, a continuation which meant, even if contact was sporadic and very much to current purposes, maintaining some kind of awareness of who was out there, what languages one needed to deal with them, and what interests they had. This presumably all became a lot more relevant when Persia was strong or active, and that information might not be something emperors carried round in their heads at all times, but the further part of the strategic map was, Mark argued, never quite empty in this period, because one never knew when it would become advisable to use it.

This all raised a goodly number of questions. I asked the obvious and perhaps unfair one about what made up Türk ethnicity, unfair because it’s a question we don’t really have the means to answer. There was also some interest in what role control of the Silk Roads played in the Türk position, which seems to have been something the Türks themselves emphasised but about which again we can say little. There were also questions about how all this looked from other perspectives, not least that of the Türks: what did they want from Byzantium, did they have policies of their own that we can guess at? To this Mark’s answer was that their priorities seemed to be to hold onto access to the Silk Roads and keep the Avars at bay or beyond, though it does seem to me that in that case their involvement with Heraclius was an own goal, as it seems likely to have made the Avars stronger, but perhaps Persia was become too much of a threat, or too rich, to ignore. I wonder about the possibility of a régime in crisis turning to outside victories to bolster its status in what was, if so, obviously an insufficient ploy. But for the most part I was happy to sit back and learn from this paper, which was immensely informative about an area of which I know far less than I should.

I couldn’t attempt to footnote this paper given the state of my knowledge, but two major references which might be good places to start were Thomas Barfield, The Perilous Frontier: Nomadic Empires and China, 221 BC to AD 1757 (Oxford 1999) and James Howard-Johnston, Witnesses to a World Crisis: Historians and Histories of the Middle East in the Seventh Century (Oxford 2010).

Seminary IX (places you can’t dig for medieval Islam)

Seminar at the IHR on Hallowe’en was Hugh Kennedy, who has recently relocated to London’s School of Oriental and African Studies, giving a paper called “Landed Estates and Incomes in the Early Islamic World”, a topic that perhaps only he could make interesting to a wider audience, though I being a charter historian and a hedgerow Islamist (by which I mean that I know a bit, but I can’t read any of the real stuff) was fascinated throughout.

The basic theory he was propounding was that in the early conquests of the Muslims, powerful or wealthy invaders were, despite the legal prohibitions against profiting from the jihad, allowed to acquire large landed estates in the conquered territories as going concerns, where they lived like the lords who had preceded them on agricultural revenues. After about 800, however, in the wake of the cAbbasid revolution, this was changed, and thereafter Islamic magnates lived off grants of tax revenue. Hugh argued that, among other things, this meant that whereas as landowners the settlers had keenly invested in irrigation and other such improvements to make their estates turn a profit, afterwards there was no such interest in infrastructure, it became harder to make such a system work because of falling land potential and the peasantry going bedouin (and therefore not paying taxes), and that basically it only lasted a generation or two before going into fiscal meltdown. The chronology of this only really came out in the discussion, which had a lot of people saying, ‘but someone must be working the land if the taxes are being paid’, and it’s still not clear, as Hugh willingly admitted, why the cAbbasids pursued such a self-destructive course.

Palace of Qasr ibn Wardan, c.560 CE

For me, though, though the actual theories and discussion and so on were the meat, the gravy was in the illustrations. Hugh has been to the places he talks about and photographed them ,and usually had more detail than we could have got from any publication about the state of their archaeology. The problem with a few of them was that there was no archaeology, however, despite their being enthralling and high-prestige sites well away from development. In fact that’s the problem: these places were on the margins, as close to the desert often as sustained investment could make cultivable. (Another set of questions revolved around climate change in Arabia, where the sources seem to support a wide range of opinions.) This in turn means that they are now well away from the prosperous heartlands where modern states have grown up. Therefore, they tend to be near borders. Bab al-Hawa, as a quick Google will tell you, is in fact now a border gateway between Turkey and Syria, where getting any kind of international dig together is a little far-fetched. Worse still however is the old Persian site of Daskarat Malka, which was once an estate belonging to Shah Khusraw II. You will find nothing about this place on the web: it’s very nearly a Googlewhack, only one irrelevant result (at least until I publish this…). It’s never been dug, although apparently the surviving structures are impressive. Why not? Because, dear reader, the site is in a bad place, and has been for some decades; it’s on the Iran-Iraq frontier. Archaeology with land-mines in it!

So I guess we’re unlikely to find out more. Which bothers me, but it bothers Hugh a great deal more and I can’t say I blame him. Similarly several of his illustrations were from 1930s French military pictures taken from biplane surveys, because since then it’s been rather difficult to do aerial photography over, e. g., Syria, unless you’re the Hel HaAvir. Add this to the losses from archives and museums in Iraq due to the war there and it just makes me want to ask: how on earth are the winners in the Middle East going to write any history?