Viking Sword Ulfbehrt

This is truly a mystery that has no explanation. When archeologists found these swords, dated back to 800-1000 AD, they couldn’t explain them. The swords seemed to have been fashioned using techniques that would not be available until 800 years later during the industrial revolution. From the metal’s composition, to the heat required to forge the blade, there’s no way the sword should have existed in that time.

Recently a blacksmith tried to recreate it using methods only used during the Middle Ages, and found it exceptionally difficult to do without resorting to modern tech.