“In English the folding knife is sometimes referred to as pocket knife, jack-knife or pen-knife,” Bjørn grinned, “but in Norwegian we call it a Foldekniv, which literally means folding knife.” The folding knife is not a new tool in Norway, there have been many folding knives found here dating back to the Viking Age. Some Viking knives had friction binders, but most of them used a closure to keep the blade open. Some were plain and basic, others had fine blades and wonderfully carved handles.
The earliest form of folding knife dates back to at least the early Iron Age. Folding knives have been found in Spain that date back to the pre-Roman era, and a folding knife with a bone handle was found in Austria that dates back to around 600–500 BC. Folding knives were popular but expensive and not widely distributed until around the year 1650, when they were produced by cutlery companies in Sheffield, England. By the year 1700 there was large-scale production of folding knives with names like Fuller's Penny Knife and the Wharncliffe Knife.