(Text + photo: H.Lyngstrøm)
Early iron technology is part of a long, complicated cultural history. And as such it is a field of research typified by extensive cross-disciplinary collaboration. Until a few years ago the research in Denmark and the rest of Europe was totally dominated by the interest of the hard sciences in isolated technological aspects. And there was a far greater focus on how iron was produced than on how the overall find-picture was to be explained. But metallurgical calculations of production and yield only really become valuable when they are related to the societies that produced, distributed and consumed the iron.
Where and how much?
The period up to 1960
The archaeological material left from ironworking was long considered aesthetically uninteresting, uncharacteristic, undatable refuse and was treated as such: already scrapped in the field. Several researchers of early iron technology worked quite independently of established science. The geographer Niels Nielsen in fact built on the work of the teacher Rasmus Mortensen when he classified the Danish iron-smelting furnaces. Nielsen’s work is typified by considerable source-critical acumen, for he thought that the geographical distribution of smelting slag only gave an approximate picture of the distribution of early iron production; as he quite justifiably assumed, the geographical distribution of the slag reflected not only the production conditions, but to a great extent also the destruction conditions. Like Mortensen, he thought that the centre of early iron extraction had been in southern and western Jutland, where the extraction slag lay ordered in clusters or rows. It was also Mortensen’s work that led to the striking concentration today of Drengsted furnaces around the river Varde Å, since his meticulous notes formed the basis of the registration by the National Museum curator Olfert Voss of iron-smelting furnaces. The attention and activity devoted to this particular type of structure has thus resulted in further find reports within the local area. Gudmund Hatt was one of the first archaeologists in Denmark to work with ethnographical parallels to low-technology iron production. He knew that the peasants in Norway, hardly a hundred years before, had roasted the bog ore before firing. So he registered all the roasted bog ore he found, and supplemented his archaeological observations with metallurgical analyses. But Nielsen and Hatt were exceptions. Right down to the middle of the twentieth century the bulk of the archaeological material from early iron technology in Denmark was left in the hands of persevering local
When and how?
From the end of the 1950s iron research was influenced more and more by the application of new dating and localization methods. This led to extensive excavation activity and typologies of iron-smelting furnaces, a major experimental effort and several metallurgical studies of iron objects. It was a time when the primary focus was on the technological perspectives of prehistoric ironworking.
In Denmark Voss excavated Drengsted, a settlement with massive traces of iron production in southern Jutland. And in 1962 content of charred straw in the slag pits could be dated to the period 260-320 AD. This created the potential for Voss’s extensive scientific work with Danish iron production, which besides excavations at Drengsted and Snorup comprised investigations of important iron extraction sites like Espevej, Skydebjerggård, Hedegård, Skovmarken, Maglegård and Hillerup. And in collaboration with Niels Abrahamsen and Tatyana Smekalova he worked out new methods of magnetic detection and demarcation of slag pits as guidelines for later excavation.
For the civil engineer Robert Thomsen the excavations at Drengsted became the beginning of work on experimental iron extraction and metallurgical analysis of prehistoric iron objects. This followed on naturally from his collaboration with Radomir Pleiner in Prague and the existing considerations of similar analyses of bog ore, iron and slag in Danish archaeological research. Thomsen’s metallurgical interest was shared by the civil engineer Vagn Fabritius Buchwald of the Technical University of Denmark, who in 1978 supplied a detailed metallurgical background for the discussion of the axe from Sønder Onsild.
Why and where to?
The period after 1990
In the 1990s Voss tried, with the archaeologists Jørgen Lund and Gert Magnusson, to view iron production in a dynamic social and economic perspective. This was to form the basis for historical and scientific work of the next few decades, when research emancipated itself from isolated technical aspects and increasingly trained its sights on the variations in the source material. Snorup was an important study site where Voss conducted comprehensive annual excavations supported, with fruitful results, by magnetic surveying. It was now seen that forest management had been the basis of charcoal production. In the landscapes at Snorup, Gødsvang, Hessel and Yderik it was primarily the iron technology of the Late Roman and Early Germanic Iron Age that led to new considerations of the cultural history, while farther north in Jutland, around Herning, the forges from the Early Roman Iron Age in the Stenbjerg district near Snejbjerg and the furnaces from Sverigesvej in Vildbjerg are examples of how the archaeologists now concentrated on uncovering the relationships among the source materials. The period after 1990 was also a time when more and more attention was turned to the ironworking of the Middle Ages, in the old Central Jutland administrative district and in Halland (now in Sweden), with the sites at Vittsjö and Tvååker.
Another tendency in iron research was the influence of traditional archaeological science, where intensive work with concepts like ‘central places’ and war booty offerings turned increasing attention on the identification of material expressions of contacts. And a method of tracing the origins of iron objects against the background of slag inclusion analysis was received with – sometimes uncritical – enthusiasm. The work with experimental iron extraction was carried on at Aarhus University, Moesgård, as well as the Historical-Archaeological Experimental Centre in Lejre.
Danish, Scandinavian and European iron research
In Danish iron research, two paths have now been laid out. One focuses on the relationship of production with settlement, the other on changes in contacts and craftsmanship. The researchers who have chosen to take the first path mainly make use of traditional archaeological excavations and magnetic detection in their efforts to create a synthesis, but also of metallurgical analyses of extraction slag and of archaeological experiments with various furnace types. The other path was originally inspired by an eastern European research tradition. It operates primarily with metallurgical analyses of objects and slag, but also with the determination of provenance, archaeological experiments with refining and forging, as well as theoretical cultural analysis. It can be said in general of present-day iron research that the linguistic perspectives have been played down, and there has been less willingness to discuss the ritualized aspects of iron technology.