They may have been dismissed as barbarians but a Bradford University expert has proved that 4th Century Europeans knew a thing or two about producing metals.

Europe's oldest steel alloy tool has been discovered by a university researcher at an ancient iron-smelting site in Heeten, Holland.

The six centimetres-long perforating punch is the earliest European example of a finished, functional tool made from two per cent carbon steel, which is more usually seen in Medieval times.

It has been examined, along with other iron artefacts from the site, at Bradford University by Evelyne Godfrey, a specialist in ancient metallurgy in the university's Department of Archaeological Sciences.

Miss Godfrey, who has written a paper on the find for the Journal of Archaeological Science, said: "This find could represent a tradition of Northern European technological innovation which was previously unrecognised, and which developed largely independently of what was happening in Romanised regions, such as Britain, at the time.

"The people who lived outside the borders of the Roman Empire have been dismissed as barbarians but the technology of this artefact is actually more sophisticated than what we see from Roman sites.

"The punch has been broken in use and then it was lost. But it was a finished, functional tool."

The punch - which was found with nails, scrap iron and bronze artefacts, such as brooches - would have been used for making holes in metal or wood.

Miss Godfrey said: "Modern punches look exactly like the ancient ones and anyone who studied metalwork or woodwork at school would have used the same sort of punch."

The findings of Miss Godfrey and her colleague, Dutch field archaeologist Matthijs van Nie, challenge the established view that high carbon steel technology was of uniquely Asian origin.

They also suggest that the steel punch was not made using iron casting but with the furnace smelting process used in Iron Age Europe.