The Sedgeford Iron project first started in 2009 when I was approached to include the Sedgeford iron knives in my PhD project. This was a nice coincidence for me since Sedgeford was the first ever excavation that I took part in. I gladly analysed the iron knives from the site.The excavations in Boneyard and Chalk Pit Field have produced in the region of 70 iron knives of varying degrees of completeness.

Gerry McDonnell and myself examined the slag at Sedgeford and this has revealed that there was evidence for smithing taking place at Sedgeford. Smithing hearth bottoms, which are classic signs of smithing activity, were found and the initial examination of sieved deposits using a magnet found hammerscale present. This strongly suggests that there was a smithy in the village, which is typical of most Anglo-Saxon settlements. More excitingly the examination of the slag assemblage revealed the presence of tap slag from a smelting furnace. Iron smelting sites in this period are very rare and this makes Sedgeford particularly important.

Looking through the iron artefacts it was clear that there was a range of iron tools, along with coffin fittings and the occasional decorative iron object. The assemblage also included some lumps of iron, which when examined closely were identified as iron blooms which are created during the smelting process. In addition to these there were some bars and rods, these were the stock iron created by refining these blooms and would have been easily traded.

Analysis was carried out on iron bars and knives from Sedgeford. To carry out this analysis small samples were removed from the knives and bars of interest. These samples were set in resin, polished and examined under a powerful microscope. Prior to analysis, all the knives were photographed and x-rayed.

The analysis of the iron bars provides detailed information about the types of iron available to the local smith. The analysis of the iron bars revealed a high proportion of phosphoric iron present, this type of iron would most likely result from the smelting of high phosphorus bog ores. These ores can be found across the UK, including nearby Sedgeford, therefore it is likely that most of the bars were the result of smelting in the settlement.

The ion knives on the other hand can provide information about the skill of the blacksmith, including the use of different iron alloys and their properties, heat-treatments (i.e. whether the blade is quenched in water) but also welding techniques. Ancient blacksmiths, much like modern ones utilised the different iron alloys to get the best out of their properties. The analysis of the iron knives from Sedgeford revealed that many of the knives were constructed using different types of iron and steel. Steel which was scarce in the Saxon period was used economically and therefore only used in small amounts to form the cutting edge. The two main methods to attach the steel would either be to weld it on to a plain iron or phosphoric iron back or to sandwich it between two pieces of iron. In the middle Saxon period it seems that the preferred method is to weld the steel to the back but in the late Saxon period this starts to change with more sandwich welds. This pattern has also been noted in knives from other sites across England. In the urban settlements the specialised nature of the blacksmith meant that they would often quench, in a liquid the objects they were working on which would create a very hard and sharp edge. This technique is also seen in some of knives from Sedgeford although not all knives were treated.

This analysis has therefore shown that Sedgeford was not only creating their own iron objects but also creating their own iron. This is rare in Anglo-Saxon England as only a handful of smelting sites have been found. Future excavations, and plotting new slag residues found, may allow us to locate the Sedgeford smithy workshop. In addition to the iron made in the Sedgeford furnaces some iron alloys, like the steel used in the cutting edges, were being brought into the settlement, indicating trade networks, to be used in special artefacts. The Sedgeford smithy was very skilled at utilising the iron and steel available, and even quenched many knives to get the best out of the steel used.

I have received funding from the Royal Archaeological Institute to undertake a study of the Sedgeford ironworking assemblage, including slag, iron artefacts and slag inclusions. The Royal Archaeological Institute is keen to encourage small projects and the involvement of part-time and amateur archaeologists, architectural historians and historians. Gabor Thomas of the Department of Archaeology at the University of Reading has also offered support in the form of the use of university laboratory facilities.

The Sedgeford Iron Project is a unique chance to investigate a rare Anglo-Saxon smelting site. Using slag inclusions it will be possible to determine whether the iron and steel used to construct knives was created at Sedgeford, i.e. if the settlement was self-sufficient, or if some iron was being imported to the site. Examination of the stock iron and blooms may reveal exactly what was being produced in the bloomery furnace.

References

Blakelock, E. 2012. Cutting Edge of Technology: How the archaeometallurgical analysis of iron knives provides an understanding of the nature of iron technology in past societies. Archaeological Review from Cambridge 26(2): 66-84.

Blakelock, E. and McDonnell, G. 2007. A review of the metallographic analysis of Early Medieval knives. Historical Metallurgy 41(1): 40-56.

Fell, V., Mould, Q. and White, R. 2006. Guidelines on the X-radiography of archaeological metalwork. Swindon: English Heritage.

McDonnell, G. 1989. Iron and its alloys in the fifth to eleventh centuries AD in England. World Archaeology 20(3): 373-382.