The Vikings attached great importance to their swords. Especially sharp or otherwise exceptionally powerful swords were given names, and passed down the generations from fathers to sons as prized heirlooms. As seen below, ancient Scandinavian bladesmiths accidentally stumbled upon a means – not understood at the time but useful nonetheless – that made their swords more powerful than those of their peers.
Scandinavian Bladesmiths and Steel Swords
Bog iron is a soft and impure ore – not ideal for making weapons and armor. However, bog iron was what people in Scandinavia had in the Iron Age. As a result, their neighbors, who had access to better iron, often had an edge over them, both figuratively and literally. Fortunately for the Scandinavians, their religious beliefs led them to unwittingly forge steel swords out of low quality bog iron. It started with the Scandinavian belief that mixing the bones of killed animals with the iron used to forge swords infused the blade with the spirit and strength of that animal.
There is no way to measure whether any resultant sword ended up with an animal’s spirit, but we do know that the strength of the resultant swords was quite good by the era’s standards. It was not because of religion, though. Instead, it was because of science that Scandinavian bladesmiths were ignorant of, but that nonetheless worked in their favor. Mixing sacrificial bones with the bog iron used to make a sword probably did not infuse the blade with an animal’s spirit. However, the sword smiths were on to something.
Unbeknownst to Scandinavian bladesmiths – or anybody else back then – bones contain carbon, as do all organic matter. Carbon added to iron produces steel. So when the sword smiths burned bones alongside their low quality bog iron, they unwittingly produced bone coal. It was the same process that transforms burned wood into charcoal. When modern scholars tried to duplicate how Vikings made swords, they discovered that mixing bone coal with bog iron when forging significantly improved the sword. Carbon from the bones penetrated up to three millimeters deep into the bog iron, and produced a significantly stronger weapon.
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Some Sources & Further Reading
Big Think – Vikings Unwittingly Made Their Blades Stronger by Trying to Imbue Them With Spirits
Sawyer, Peter Hayes – The Age of the Vikings (1972)
