I’m not usually the kind of historian who gets ultra verklempt about weapons, not even Medieval ones. But these Viking-era swords were just mighty bitchin.
From about 750-1100 CE, “Ulfberht” swords emerged in northern Europe, and they were different than the rest. Vikings and other peoples in northwestern Europe had already improved sword-making techniques: they put a central groove called a “fuller” in the middle of the blade to make it lighter and more flexible, and they widened the hand-guard for better protection.
But about 170 swords with the inscription +ULFBERH+T have been found, and their make was far superior. The carbon content was much higher than other swords of the time, making them even more flexible and durable. The steel that they were built from, “Crucible steel,” actually had to be imported from lands east of Europe — one source records it coming from near the city of Herat in modern Afghanistan.
There was even a trade in counterfeit Ulfberht swords (inferior carbon amounts, and incorrect spellings of the name).
Ulfberht’s identity has long been debated, but weapons meant a great deal to the Vikings. My favorite testimony to this fact are the various names given to prized weapons (albeit not all of them swords, because axes and especially spears were in use too) appearing in Old Norse-Icelandic sagas: “Brynjubítr” (byrnie/chain-mail coat-biter), “Saetarspillir” (peace/truce-breaker), “Fótbítr” (foot/leg-biter), and “Rimmugygr” (Battle-hag).
Sources: _Vikings Fact and Fictions_ Kirsten Wolf and Tristan Mueller-Vollmer ABC-CLIO Santa Barbara CA 2018, pp 116-118, I added yellow to an image of an Ulfberht sword found on https://swordencyclopedia.com/ulfberht-sword/