Friday, 11 October 2019

Alfred the Great and the Vikings: new evidence from the London Monogram coinage

Coinage is a vital historical source for understanding the history of early medieval Britain. It can be studied from a range of different perspectives to tease out historical details - the design of coins and the names of moneyers betray cultural influences; the location of mints can help to define territories; the symbols on coinage depict a language of power. As part of the ERC project, we are analysing early medieval coins from an altogether new perspective, that of the metal alloy itself. This, we hope, will reveal likely sources of silver, casting new light on the wealth of Anglo-Saxon England.  

The coin shown below was issued by Alfred the Great, King of Wessex (ruled 871-99 AD) and is known as a ‘London monogram’ type because it depicts a monogram of the name LVNDONIA (London). On the other side, Alfred is depicted as a Roman emperor, with his name and title EL FR ED REX appearing on either side of his portrait.  Modest? No, but Alfred was following long-established precedent in linking his authority to a Roman Imperial past. 


On the left the coin reads ELF REDREX. On the right is the monogram for LVNDONIA.

The London monogram coinage was a celebratory issue, marking Alfred’s newly won control over the city of London in the early 880s (whether this control was won from the Vikings, or the Mercian King Ceolwulf, who mysteriously disappeared in 879 is debated, but the latter is more likely).  Control over the city was important, not only because it enabled access to its valuable port, but because London was a frontier town, located close to the ‘border’ between Anglo-Saxon England and the Danelaw. It was thus a critical defensive stronghold against Viking incursions.

Earlier this year, we had a chance to capture lead isotope and trace element data for a London Monogram coin as part of a broader analysis of Anglo-Saxon and Anglo-Viking coins held in the collections of the British Museum (some of the coins, sitting neatly edgeways in their tray, are shown below - the small bits of silver in the blu-tack are our standards).

The analytical beam focused on the edge of the coins. Using laser ablation means there is no visible damage to the item.  
The analysis was undertaken at the NOCS, University of Southampton, with Dr Chris Standish.
(Image copyright Jane Kershaw and Chris Standish)

The results were intriguing. While most of the Anglo-Saxon and Anglo-Viking coinages clustered in two distinct lead isotope groups, the London Monogram coinage was an outlier. Various interpretations are possible, but it seems that, unlike other Anglo-Saxon coins we analysed, it was made with silver from a mix of sources, including Islamic dirham silver. 

Whether this silver was in the form of actual dirhams, which circulated freely as bullion within the Danelaw, Scandinavian rings and ingots, which had themselves been made from Islamic silver, or Anglo-Viking coins minted in the Danelaw is an open question - either, or all, are possible. Whatever the case, the results show that for all we think of the Vikings taking silver out of England, they also bought it in. There is a pleasing irony here that Alfred’s London Monogram type, minted to ceremoniously record his authority over a Danelaw frontier town, is made, in part, from Viking wealth.



New project: 'Silver and the Origins of the Viking Age'


In March 2019, I started a new ERC Starting Grant project, ‘Silver and the Origins of the Viking Age’. I have a great team: Dr Stephen Merkel, an archaeomaterials expert specialising in silver (based at the University of Oxford), and Jani Oravisj√§rvi, a specialist in early medieval Islamic coins (based at the University of Oulu, Finland). 

We are aiming to re-evaluate where, when and why the Viking Age began, through an interdisciplinary analysis of Viking silver. We are conducting lead isotope and trace element analysis of hundreds of Viking artefacts, enabling us to answer questions such as: where did the Vikings get their silver from? When did silver first reach Scandinavia and why was it so highly valued? 

Full details of the project: its aims, scope and methods, can be found here.

We have hit the ground running and already have lots of analyses under our belt. I will continue to use this blog to highlight our work.

Tuesday, 4 December 2018

Laser ablation analysis of Viking silver

One of the main barriers to analysing silver objects is getting permission to sample destructively. Understandably, museum curators are often reluctant to allow researchers to drill or otherwise remove metal samples from their precious objects for analysis in the lab.

Other means of analysing silver objects that don’t leave any visible damage are therefore of great interest. Analysing objects by laser ablation, which is coupled to a mass spectrometer and can be used for both lead isotope and trace element analysis, offers one such method. Critically, unlike XRF and other analytical methods that measure only a layer of a few micrometres, laser ablation gets below the surface of an object to measure the bulk alloy. This ensures that the results we get aren’t affected by silver surface enrichment: an issue known to affect Viking silver. 

Laser ablation has the same high accuracy trace-element/lead isotope capabilities and low detection limits of solution-based analysis (requiring destructive sampling), and has returned precise and reliable results for both types of analysis in recent work.  Most importantly, the small diameter of the laser ablation spot is about the diameter of a strand of hair. This means that the method is not visible to the naked eye, allowing for the characterisation of museum artefacts that would otherwise be barred from analysis. Since it requires no sample preparation, laser analysis is also cost- and time-efficient. So, win, win. 

A huge gold silver neck-ring/ torc from the Bedale hoard. This item
is far too large for the laser ablation chamber. Fortunately for me,
a small fragment from the ring also survives, and could be used.
So far, there have been very few analyses of silver via laser ablation methods. But a few weeks ago, I analysed some of the Bedale hoard objects this way with Dr Simon Chenery at the British Geological Survey (for a nice video of the Bedale hoard, see here). We managed to analyse 18 of the 37 silver items in one working day (not bad going at all). A constraint was fitting the items within the laser ablation chamber (measuring about 10 by 10 by 2 cm). There was no way that the enormous silver torc from the hoard, seen in the picture above, was going to fit!  But by careful arranging of the other items, we fit several ingots in one analytical session. By having them all facing inwards in a clock-like manner, we ensured that the laser didn’t have to move about too much as it jumped from one object to the next. 

Ingots from the Bedale hoard snuggly positioned on the laser ablation tray
Each object was ablated in three different areas, for 150 seconds. The laser beam quickly penetrated the surface layers, suggesting that the effects of surface modifications were not deep (interestingly, this is a different result to that found on medieval silver coins). If you strain your eyes, you can see this in the way that the peaks recorded in the concentration depth profiles for first 5 seconds or so of analysis quickly reduce to a fairly stable level. 

Live results. The laser beam quickly penetrated the
surface of the silver ingots. 
The results were extremely interesting. Since we already have lead isotope ratios for these objects and have also analysed the entire hoard via portable XRF (the surface-only method), we now have lots of different data points for the same objects. This is starting to reveal interesting patterns regarding the likely sources of silver, as well as the limitations of the XRF method - the main method of analysis in the past. More on this in later posts....

A big thanks to Simon Chenery at the BGS, as well as the fantastic curators at the Yorkshire Museum: Andy Woods, Lucy Creighton and Emily Tilley.


Monday, 9 April 2018

PODCAST: Dawn of England: Viking Archaeology

http://www.bbc.co.uk/programmes/p0638qq8
A 20-minute podcast for BBC Radio about the Vikings in England: why were they so successful, and what is the value of the Watlington hoard for assessing the reign of Alfred?

Tuesday, 30 January 2018

Tracing Viking loot

During the ninth century, Vikings launched sustained raids on the Continent. Their aim was to acquire portable wealth: gold and, especially, silver. By all accounts, they were remarkably successful. So why does so little Viking loot survive in the archaeological record?

The sums raised by the Vikings through bribery, theft and extortion were enormous, especially when raiding intensified in the mid ninth century. Surviving documentary sources tell us that Vikings on the Somme extracted 5,000 lbs. of silver in 860. Two years later, another group on the Loire gained 6,000 lbs. Exact sums are not always mentioned, but a reasonable estimate is that raids on the Continent earned the Vikings a total of 7 million Carolingian pennies (or c. 30,000 lbs of silver). In today’s money, that’s somewhere between 85 and 170 million British £ (maths courtesy of a 10th century Anglo-Saxon law code, and reckoning on the, rather variable, modern price of sheep).

A Carolingian coin of Lois the Pious, minted at Melle, western France between 822 and 840. It was found in Louth, Lincolnshire - one of a growing number of single finds of Carolingian coins from England. PAS 'Find-ID' F6C6E1


Despite this, only around 200 Carolingian coins are recorded within Scandinavia. Even more incredibly, these coins date mainly to the 820s and 830s, indicating that they arrived in Scandinavia before the high point of raiding in the middle of the ninth century.  Carolingian coins are also found in England and Ireland, both as single finds and in Viking-Age hoards. But even here they are not especially numerous, even in hoards deposited soon after the main events, in the ninth century. The recently-discovered Watlington (Oxfordshire) hoard, deposited in the late 870s, contains only 2 Frankish pennies out of a total of c. 200 coins. We’re talking a trickle, rather than a flood.

A selection of items and coins from the Watlington hoard, deposited in the late 870s. It contains just 2 Carolingian coins out of c. 200 coins - the remainder of which are 9th century Anglo-Saxon issues. One of the Carolingian coins is the larger-than-average coin in the top centre. They were slightly heavier than contemporary Anglo-Saxon coins.

So, what happened to all the Continental coins? Even if we accept that the Vikings sometimes received other goods (cattle, grain, wine) in place of silver, and spent a portion of this wealth (on land, for instance), we would still expect a significant proportion of coins to end up back in Scandinavia or in other areas settled by Viking groups in the ninth century. Do the written sources exaggerate the amount of European wealth that ended up in Viking hands? Or did the Vikings simply melt down most of the coins to make silver ingots and rings (which were, after all, easier to transport)?

Because the act of melting down the silver effectively masks its origins, the only way to answer this question is through metallurgical analysis. This has only rarely been undertaken for Viking silver. But I recently had the opportunity to analyse the silver objects (ingots, rings and a brooch) and contained in the Bedale, Yorkshire hoard, probably deposited around c. 900 AD. Together with Jane Evans at the British Geological Survey, I sampled all 37 silver artefacts from the hoard, obtaining lead isotope data for each item. This data gives an isotopic signature of the small amount of lead that is present in the silver. It can be compared with the isotopic ratios of lead in Carolingian pennies, and other likely source coinages, to identify relationships between the coins and the silver artefacts. It has the potential to reveal where the silver used to make ingots and rings originally came from.  

This is work in progress (you can see a short video about it here, and at the Vikings: Rediscover the Legend exhibition, currently on at Southport Atkinson centre). I'm going to write future blog articles about how the analysis as a whole sheds new light on the question of where Viking loot ended up. But here I wanted to share one, particularly exciting result. 

The two Hiberno-Scandinavian (ie. Irish-Viking) objects in the Bedale hoard seem to have lead isotope ratios that match closely those of coins produced at Melle in western France: a major Carolingian mint in the ninth century. The results would seem to suggest that they were made by melting down Carolingian coinage, perhaps coinage that was brought to Dublin in the years before c. 900. This is interesting, because the Cuerdale hoard, deposited c. 905-10 in Lancashire, north-west England, contains an unusually large number of Carolingian coins (about 1000), many of which come from western France and may be the result of a Viking raid on Aquitaine in 898. Much of the Cuerdale hoard silver came from Ireland - what we may be seeing is an influx of Carolingian coins into Dublin or the Irish Sea region shortly before the turn of the tenth century.  

A Hiberno-Scandinavian broad band arm-ring from the Bedale hoard. Its lead isotope ratio is consistent with 
that of coins produced at Melle in western France, suggesting it was made from melted-down Carolingian pennies. Photo copyright Yorkshire Museums.
In this case, then, it seems likely that silver coins obtained by the Vikings on the Continent were taken to Britain or Ireland where they were either preserved as coins or melted down into ingots and rings that the Vikings could store, trade and/ or wear as appropriate.  We are beginning to unravel the history of Carolingian coins once they passed into Viking hands. Would silver rings and ingots from Scandinavia reveal the same link with Melle? 
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