The manufacture of metal alloys played an important role for the Vikings – they used it in everyday objects, for weapons and jewelry. Archaeological finds from the Danish Viking settlement of Ribe now show how the metallurgy techniques of the Vikings developed over time. They document how crucibles and alloys were optimized and standardized from the 8th to the 9th century.
The town of Ribe on the west coast of Denmark was a trading port for the Vikings in the early Middle Ages – and an important metalworking center. “Ribe’s role as a hub of northern European sea trade gave local artisans access to raw materials and markets, which encouraged the production of metal alloys and metal objects in the place,” explain Vana Orfanou of Aarhus University and her colleagues. Thousands of crucibles, slag residues, pieces of metal and fragments of casting molds bear witness to this metalworking process.
Change with the beginning of the Viking era
Orfanou and her team have now examined some of these finds more closely to find out more about the beginnings of metalworking in this Viking branch. To do this, they analyzed 1,126 samples of crucibles and casting molds, finished metal objects such as keys and jewelry as well as metal bars and slag residues from the time between 700 and 850 AD for their metal content and chemical composition. “By examining both the tools and the finished items, we get a better understanding of which metalworking techniques were used in Ribe and how they have evolved over time,” says Orfanou.
Indeed, there were clear differences between the early period up to around 790 and the later period, which was dominated by Vikings. Initially, the craftsmen in Ribe used clay crucibles with a rather low and strongly varying aluminum content, but later the fired crucibles contained more aluminum-containing minerals. This gave them better heat stability and suggests that the metallurgists later specifically looked for the clay that was cheap for it, as the researchers report. Even in this early period, craftsmen also preferred to produce alloys from more than two metals, but their composition still fluctuated greatly.
Standardization in alloys and processes
That changed after 790: From this time on there was a trend towards more systematic and standardized alloy production. “We are documenting a series of rapid technological advances at the beginning of the Viking Age. Within a century, the craftsmen changed their technique from the rather random mix of metals to an optimized process in which specific alloys were produced. “For example, bronze and brass with a high lead content were mainly used in the early days and for practical objects such as keys – possibly because lead was soft and easy to work with.
Later, however, harder alloys with a higher zinc content dominated. Zinc-rich bronze was mainly produced for everyday objects, while the shiny gold brass was used for jewelry. “Alloy production in the later phase is linked to the emergence of completely new types of ornaments, which show stronger modeling and probably also go back to new casting techniques,” report Orfanou and her colleagues. In her opinion, the change in technology and the introduction of new alloys could be due to the arrival of new craftsmen, but also to the exchange of experience with metallurgists from other Viking branches.
“The Viking Age marked a crucial turning point in history, when communication across seas in Northern Europe grew exponentially,” Orfanou explains. “The development of crafts such as metallurgy gives us unique insights into the cultural and social consequences of this well-known example of ‘proto-globalization’.”
Source: Springer; Technical article: Archaeological and Anthropological Sciences, doi: 10.1007 / s12520-021-01308-1