Proof Bronze Age Iberians Made Steel Tools 1,000 Years Before the Romans!
A study of elaborate 2,900-year-old carvings in stone monuments found in Portugal has revealed a rather amazing fact. It seems these Late Bronze Age engravings could only have been made with hardened steel tools, of a type that had previously been found only in excavations from later times.
The use of tempered steel tools or instruments to make rock carvings suggests that some kind of small-scale steel industry had developed on the Iberian Peninsula by the year 900 BC, which is one century earlier than steelmaking was believed to have started in the area.
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This paradigm-shifting conclusion emerged from research carried out by a team of archaeologists from Portugal, Spain and Germany, who were led by Ralph Araque Gonzalez, an expert in prehistoric archaeology from the University of Freiburg. The scientists published the results of their work in the Journal of Archaeological Science , detailing how they discovered that only steel tools could have been used on the stone monuments.
Was Steel Needed to Etch Such Hard Rock?
For the purposes of this study, the researchers looked at engraved five-foot-tall (1.5 m) pillars of stone known as stelae, which have been found in abundance at various Iberian Peninsula sites . The stelae in question feature intricate and carefully prepared carvings of human beings, animals, weapons, chariots and ornaments, imagery that is familiar to archaeologists and historians who have studied the art and iconography of ancient societies.
What is most interesting here is that the stone used to create the Late Bronze Age stelae in Portugal was an extraordinarily hard rock known as silicate quartz sandstone. Tools made from a metal harder than this cut-resistant stone would have been required to create engravings. According to Gonzalez and his research team only steel tools could have gotten the job done.
More specifically, this kind of stone could only have been engraved using tools made from steel that has been tempered, meaning it had been treated with high heat to make it stronger and more resistant to fracturing. “This is an extremely hard rock that cannot be worked with bronze or stone tools,” Gonzalez said in a University of Freiburg statement . “The people of the Final Bronze Age in Iberia were capable of tempering steel. Otherwise they would not have been able to work the pillars.”
The study found that the stone could only have been engraved using tempered steel, created under high heat conditions. (Ralph Araque Gonzalez / University of Freiburg )
Testing the Tempered Steel Hypothesis
But this statement is not based on logical deduction alone. To prove that only tempered steel could do the trick, they decided to do some hands-on experimenting. In collaboration with a professional stonemason, Gonzalez’s team attempted to recreate the ancient engravings in silicate quartz using tools made from different materials, including (among others) bronze, stone and tempered steel.
While the steel chisel used in the study did have to be sharpened repeatedly during the carving process, the researchers were able to make engravings in the hard rock with it. They were unable to do this with the other tools, as they predicted before the experiment began.
It should be noted that the steel chisel used in the study was not chosen randomly. It was actually a replica of a real and quite ancient steel chisel, a well-preserved tool that was unearthed in the early 2000s at a site in Portugal known as Rocha do Vigio.
Like many of the Late Bronze Age stelae found on the Iberian Peninsula , the chisel had previously been dated to around the year 900 BC. Engravers working at this time would have had access to sharp steel tools, it appears, confirming that steel instruments could very well have been used to make the carved stelae.
Measurements of the chisel showed it contained enough carbon (more than .3 percent) to be considered steel (less carbon and it would still be classified as iron). Notably, the researchers also found traces of iron minerals close to the Rocha do Vigio site, indicating that craftspeople could have sourced their metal locally.
“The chisel from Rocha do Vigio and the context where it was found show that iron metallurgy, including the production and tempering of steel, were probably indigenous developments of decentralized small communities in Iberia, and not due to the influence of later colonization processes,” Araque Gonzalez said, crediting the prehistoric locals for their ingenuity and inventiveness.
The chisel from Rocha do Vigio, length ca. 18 cm. (Ralph Araque Gonzalez / University of Freiburg )
Honoring Iberia’s Original Master Steelmakers
Before this new discovery, the earliest proven use of hardened steel in Iberia was linked to the Early Iron Age (800 to 600 BC). This was only a short time before the Late Bronze Age (1,000 to 800 BC) stelae were produced, suggesting a continuity of the region’s steelmaking culture that bridged the gap between the end of one Age and the beginning of the next.
Evidence shows that large-scale steel production for tools and weapons only began on the Iberian Peninsula during Roman times, in the second century AD. But this steel was of apparently poor-to-mediocre quality, as was revealed by tests of metal objects from that time that revealed a low level of carbon content.
During the late medieval period, European blacksmiths finally progressed far enough in their work to produce superior tempered steel. But it seems they may have only been recreating the achievements of Iberian blacksmiths who lived more than 2,000 years before them. These skilled craftworkers were making steel tools that were strong and sturdy enough to carve distinctive images in some of the hardest rock found anywhere on the planet, which represents a remarkable achievement in any time period.
Top image: Replica of Capilla stelae. Source: Ralph Araque Gonzalez / University of Freiburg
By Nathan Falde