Oregrounds iron

Actually, the term is more specialised, as all the Swedish Walloon forges made iron from ore ultimately derived from the Dannemora mine.

The process was devised in the Liège region, and spread[4] into France and thence from the Pays de Bray to England before the end of the 15th century.

[8] Swedish law required bars of iron to have the forge's mark stamped into it for quality control reasons.

This made it particularly suitable for making steel, oregrounds iron was an indispensable raw material for metal manufactures, particularly the Sheffield cutlery industry.

The trade in oregrounds iron was controlled from the 1730s to the 1850s by a cartel of merchants, of whom the longest enduring members were the Sykes family of Hull.