Tuhandeaastane nuga. Eesti 10. sajandi paksuseljalise võitlusnoa sepistamisest / A Thousand-year-old Knife: On the Forging of a 10th-century Estonian Thick-backed Battle Knife

Abstract

This article examines the manufacture of thick-backed battle knives used in Estonia in the 10th century, focusing on the forging technology employed in the production of the three-layered blades of this type of knife. The research methodology involved the examination of archaeological artefacts and practical blacksmithing experiments. The process of manufacturing a three-layered blade was reconstructed, and the technical challenges involved were assessed.

Battle knives were important weapons in Estonia at least until the 11th century, when swords became more widely available and replaced them. Thick-backed battle knives were relatively long weapons, often measuring 27– 55 cm in length, and one of their distinguishing features was a particularly thick back. On some specimens, the blade was over 10 mm thick at the tang, which meant that these knives had a wedge-shaped cross-section.

Among earlier researchers, archaeologist Mati Mandel demonstrated that most battle knives were manufactured using a three-layer technique. A thin layer of carbon steel was placed at the centre of the blade, surrounded on both sides by layers of softer iron. One of the challenges of the experiment was working out how to forge such a long blade while ensuring that the central layer of steel remained consistently aligned with the centre of the blade throughout its entire length. In preparation for the experiment, a total of thirteen such blades were examined from the archaeological collections of the Estonian History Museum and Tallinn University. It emerged that the middle layer of steel in most of them was approximately 2 mm thick and ran evenly along the entire length of the blade. Examination also confirmed that the thick-backed battle knives were masterfully crafted, technologically sophisticated weapons.

Three tests were carried out using bloomery iron and old wrought iron, which were selected as the materials for the blade’s side layers. Bloomery iron was produced during earlier experiments in iron smelting. It is a porous mass of iron obtained by direct reduction from ore and contains a large amount of slag. To make it usable, the material had to be repeatedly heated, forged, folded and remelted. After processing, it transpired that only about a third of the original mass of the nearly 700g piece of bloomery iron remained. However, the resulting 24-layer structure was reminiscent of the wrought iron used in ancient knives.

Old wrought iron was cut into pieces and processed repeatedly to improve its quality, producing a multi-layered material resembling ancient wrought iron. The advantage of this method was that it required less labour than producing material from bloomery iron. Once the blade’s side materials were ready, work began on manufacturing the three-layer blades. The steel layer was made from modern U8 carbon steel, which has a carbon content of around 0.8%. A total of three blades were produced. The first blade was made from material obtained from bloomery iron. As there was too little material from the bloomery, the blade turned out shorter than expected. For the second and third blades, old wrought iron was used, enabling longer blades to be produced that were more comparable in size to historical artefacts.

The experiments showed that making a three-layered blade requires experience and careful planning, but does not necessarily require any special tools. The most challenging aspects were keeping the steel layer centred along the blade’s entire length and forging its sides symmetrically. Etching the finished blades brought out the patterns in the layered material. The texture of the material obtained from bloomery iron was particularly interesting, thanks to the traces of slag and the combination of different layers of iron. In contrast, old wrought iron produced a calmer and more uniform pattern.

The study confirms that the three-layered construction of the thick-backed battle knives was technically well thought-out and masterfully executed. Practical experiments have helped us to understand the skills and working methods of ancient blacksmiths. We can conclude that the production of high-quality, dimensionally accurate weapon blades in ancient times, when all work was done by hand, required a very high degree of craftsmanship.

Keywords: battle knife, thick-backed knife, ancient weapons, ancient forging reconstruction, smithing, three-layer blade, bloomery iron, wrought iron