Tuesday, April 03, 2007

Iron from Celtic to Early Medieval

I got this request from fellow An Droichead member Catherine Crowe. Since it was going to be easier to just send her the information than reference dozen of fragmentary sources - the following piece developed. (This is a very long article!)

> I am looking for pictures and information
> I am looking for 'Celtic' areas and comparing to
> materials from the Iron age to show development in
> this particular medium (so Europe generally and
> Ireland specifically for 'place' and generally from
> 6th-12thc time wise)
> The materials I am dealing with in my paper are
> bronze, clay, iron, wood, stone, silver and gold. I
> seem only to be lacking in the iron area, probably
> becasue that material is not as 'decorative' in this
> period.

It may not be possible to point you to a single source that will cover the information that you are looking for. The objects and most importantly the mechanics of archaeology are against you. What I know about the following has been pieced together from a lot of individual sources (text, objects, conversations).

In very short hand - iron remains a valuable material. This both because of the raw effort required to create it, plus its utility, thus connection to important objects. Working against this is a preservation problem, further narrowed by the change in burial customs into the Christian era.

Between the Celtic Iron Age and the 'Dark Ages' (post Roman through Viking Age to Early Medieval) there is a general but small improvement in the technology of making iron. (I'm leaving the Romans out of this - there is a jump forward in size and efficiency under the Romans - which drops back after they leave Brittan.) Celtic Iron Age small bowl furnaces with natural draft producing maybe 2 - 5 kg is replaced with a short shaft furnace plus bellows that produces closer to 5 - 15 kg. So the production of iron does increase, but not by a huge factor. (The next jump will come in the Early Medieval period with the application of water power for bellows and trip hammers.) One important limit imposed by hand tools is that the largest width of iron sheet found in any pre Medieval object is about 20 cm.

Iron is prized in both Celtic and Dark Ages for its high utility. This results in a huge range of quality and complexity of objects being made from it. Everything from nails and rivets through to complex cauldron hangers and pattern welded swords. The raw versitility of the material leads it to be used for a wider range of objects than any of the other materials on your list - with only bronze coming close in depth of applications. An axe may range from a simple wedge of plain iron through to an elaborate show piece with inlaid gold or silver.

Unfortunately, to aspects of iron greatly warp any general assessment of the objects made from it. First is its relative lack of preservation. In the presence of almost any water at all, iron reverts from metal to crumbles of iron oxide (rust). With the climate of North Europe as it is - almost any iron object placed into the ground turns into a corroded mass in mere decades. Second is that same utility mentioned earlier. It is quite possible to convert any iron object through the hand of the smith to another iron object. The effort required to do this is so much less than creating new iron from ore. This combination of high utility and ease of transformation leads many iron objects to have been re-cycled into new ones. (You will find the same factors at work for bronze and gold.)

Most importantly, the artifact evidence in the culture and time you have defined is profoundly influenced by the customs of the early Christians. There is a sharp break in availability of artifacts from the pagan cultures who believed in an 'active' after death condition and that of the Christians, who stressed spirit over body. Christians were just not buried with their life goods. This leads to a situation where its much easier to get a picture of daily life for a Norse resident of Ireland than his Celtic neighbors.

There can be an effort made to extend Norse / Saxon cultural practices over into Celtic residents in the same geography. This may not be a huge stretch, as there are many similarities, and certainly the underlaying technologies are very close and the access to raw resources is virtually identical.

So - what does this mean in terms of iron objects?

There is a large volume of iron used for the merely practical. Here I'm referring to boat rivets especially, but also construction nails, simple hooks, straps, hinges and the like. To compare this to the earlier Celtic Iron Age, there would be hardly any use of bronze as a construction material. (Note that wood remains the single most dominant material for all kinds of objects)

Tools of all kinds are made of iron. Obviously this includes cutting edges. Although this is also the case for the Celtic Iron Age, there is a significant improvement in the physical methods used to construct iron cutting edges especially. Wider use of carbon alloy ('steel') is being made. This often is in the form of small pieces of harder steel welded into place to create cutting edges. The raw number and range of iron tools increases.

There are now a larger number of functional cooking tools of iron. This includes both flat dish and 'fry pan' types, spiral cooking irons, and a wide range of spits that range in size and include large forks. In this group of functional objects can be put the large segmented and riveted iron pots and cauldrons. Those range in size considerably. All these objects would have been 'household' equipment. Although cauldrons and pots are also found made of bronze / copper alloy, there is some evidence that there may have been some problems with obtaining this raw material into the Viking Age. In this group could also be placed 'strike a lights' - steel strikers used with flints. These are often overly complex forgings, so appear to be presentation objects. Again these are more likely to be household rather than personal equipment.

Iron is used for jewelery, although not commonly. These will be smaller, less elaborate pieces, more likely to be functional than highly decorative. I have seen bracelets and torcs, mainly formed of twisted square rods. Simple pennaular brooches are also found - there are a number of samples. There is at least one 'charm bracelet' with small iron tokens looped over a twisted iron band. (These all Scandinavian.)

There is only ONE SINGLE iron tripod artifact sample from the Viking Age (the one from Oseberg - c 825). This should be considered a presentation object made for a burial, not a functional tool. For that reason it can be grouped in with the ornamental cauldron hangers. There are a good number of these that have been found, again in association with royal caliber burials. The complex hanger found at Sutton Hoo (Saxon c 625) being the best known example. Hanging in the centre of the hall, these hangers are expressions of wealth and status, both in terms of volume of metal and complexity of craftsmanship. A careful look at the hangers as they would have been used will show that the most complex elements are most often placed at roughly four feet and five and half feet from the floor as they were mounted. This corresponds to sitting and standing eye height - obviously intented for maximum visual impact.

As with the Celtic Iron Age - it is with objects related to combat that the highest value is placed.
Unlike the earlier period, ever increasing use of armour is being made, and more and more that armour includes iron. The technology of iron production, and more important the limits imposed by hand tools, makes the forming of large sheets of iron quite difficult. For that reason, the only armour containing plates of iron are helmets. These are almost always segmented and riveted of smaller plates (construction quite like cooking pots). Helmets are extremely rare in the artifact record, there are only about a dozen surviving from the entire Dark Ages. Use of iron chain maile increased throughout the period. Maile represents a huge investment in skilled labour to produce, but in a way is less technologically demanding that creating plates. Because of this huge labour cost, maile is also seen as a status symbol. (Saga references where leaders boast of their ability to equip a large troop with maile shirts.)
Weapons, ranging from fighting knives through to spears, axes and swords, are found with highly decorated surfaces and furnature. It is important to remember that at core these all remain highly effective combat tools, and function is never scarafised for mere orimentation. Weapons often bore names, and high quality weapons were heirloom objects. It was quite possible for a sword to have a greater reputation than the man who owned it.

It is in swords that the apex of the blacksmiths art will be found in the Dark Ages, most specifically at the hands of the Saxons from southern Denmark c 600 AD. The amazing sword from the Sutton Hoo burial would have be created about that date. The technique of 'patern welding' is first seen in blades from the latter Roman era, about 100 - 200 AD. The technique involves stacking hard steel and soft iron in layers, then welding these into a solid billet. This is then drawn to a long rod, which is then twisted. Several such rods, with twists in opp[ostie directions, are then welded together to form the core of a sword blade. The function of these twisted layers is like a set of coil springs running down the centre of the sword. This creates a blade that is both tough but flexible. The sword from Sutton who is the single most elaborate of the type, with eight core rods which alternate twists and straight prortions right and left / side to side / top to bottom. It is important to note that while pattern welded blades are relatively common during the Viking Age, the technique is essencially lost by the time of the Crusades. Pattern welding is also seen on knives from this era, where is serves no practical function save its decoration and status.

The text references to establish all this will tend to fall into two broad types. You will find topic driven general overviews, which will tend to focus on mainly the high end 'royal caliber' objects. A book with a title like 'Monistaries in Early Ireland' may only have a couple of illustrations of iron objects, and will be unlikely to give much context information for them. More useful to picture a range of objects may be exhibit catalogs, but these often prove very short written details. On the other hand will be the primary documentation of archaeological excavations, which are hard to find and difficult to wade through.

Some texts that you may find helpful for artifact images:

The Sutton Hoo Ship Burial - A.C. Evens (ISBN 0 7141 0544 9)

From Viking To Crusader - Rosedahl & Wilson (ISBN 0 8478 1625 7)

Anglo Scandinavian Ironwork from Coppergate - P. Otaway
(ISBN 1872414 29 X)

It turns out that although there is a huge amount of iron objects from Woods Quay in Dublin (c 900) none of this material has been described in the literature yet.

No comments:


February 15 - May 15, 2012 : Supported by a Crafts Projects - Creation and Development Grant

COPYRIGHT NOTICE - All posted text and images @ Darrell Markewitz.
No duplication, in whole or in part, is permitted without the author's expressed written permission.
For a detailed copyright statement : go HERE