Noreia

Noreia is an ancient lost city in the Eastern Alps, most likely in southern Austria. While according to Julius Caesar it is known to have been the capital of the Celtic kingdom of Noricum, it was already referred to as a lost city by Pliny the Elder (AD 23 – AD 79). The location of Noreia has not been verified by modern researchers.

The kingdom of Noricum was a major provider of weaponry for the Roman armies from the mid-Republic onwards. Especially the Roman swords were made of the best-quality steel then available, the chalybs Noricus, from this region. The strength of iron is determined by its carbon content. The wrought iron produced in the Greco-Roman world generally contained only minimal traces of carbon and was too soft for tools and weapons. It thus needed to be carburised to at least 1.5% carbon content. The main Roman method of achieving this was to repeatedly heat the wrought iron to a temperature of over 800 C (i.e. to "white heat") and hammer it in a charcoal fire, causing the iron to absorb carbon from the charcoal. This technique had been developed empirically, as there is no evidence that ancient iron producers understood the chemistry involved. The rudimentary methods of carburisation used rendered the quality of the iron ore critical to the production of good steel. The ore needed to be rich in manganese (an element which remains essential in modern steelmaking processes), but also to contain very little, or preferably zero, phosphorus, whose presence would compromise the steel's hardness. The ore mined in Carinthia (S. Noricum) fulfills both criteria to an unusual degree. The Celtic peoples of Noricum (predominantly the Taurisci tribe) empirically discovered that their ore made superior steel around 500 BC and established a major steel-making industry around it. At Magdalensberg, a major production and trading centre was established, where a large number of specialised blacksmiths crafted a range of metal products, especially weapons. The finished products were mostly exported southwards, to Aquileia, a Roman colony founded in 180 BC.

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