The word Ulfberht is a Frankish Name. Perhaps it is an indication of its actual place of manufacture, but the Ulfberht sword was a Viking Sword . All of them were manufactured by tradesmen who practiced a tightly held manufacturing line between 850 and 1100 AD. Ulfberht may very well have been one of the first actual brands. The name meant quality and precision and statusas evinced by the fact that the name was meticulously etched on each blade.
The quality of the iron was better than the iron almost anywhere in Europe. Bog Iron is available in Ireland and in northern Europe, but it was not rigid. Moltenr iron has to be brought to 1500 degrees in a kiln and that is a high bar for the early middle ages. Some Ulberhts were a fairly high quality steel as well.
The Franks were turning out these swords and the Frankish monarch wanted to make sure that Ulfberht could not be traded to enemies. Even he couldn’t stop arms trade.
Source: Wiki, Shineodreams