Viking sword

The Viking sword was the primary weapon of the viking and main type of sword used in North Western Europe during the Viking Age. Although called "Viking sword", this style of sword was not exclusively limited to Vikings and was used by other people.

Morphology
The Viking sword was the primary weapon of the Viking. It was a development of the Roman spatha, evolving out of the Migration Period sword in the 8th century, and into the classical knightly sword in the 11th century with the emergence of larger cross-guards. The Viking swords were pattern welded which gave the blade extra strength as the core was made of springy iron and edge of hard steel. Of particular note is the "Ulfberht" subset, which used steel of higher purity and carbon content than its peers in the region that may have been imported in ingot form from the middle or far east.

Blade length varied from 71 to 84 centimeters. Early examples have single, deep, wide fullers running the full length of the blade. Later examples have multiple narrow fullers. A fuller reduces the weight of the blade without compromising its strength. This weight reduction would allow the wielder to swing faster and harder strokes. Later swords also had more tapered points for increased effectiveness against chain mail.

All have short single-handed hilts with pyramid, lobed or cocked-hat style pommels. Pommels were made of iron and were heavier than on the earlier Migration Period sword, acting to counterweight the blade.

Ulfberht Variants
Of the thousands of Viking swords that have been recovered, 171 of them, all made between 800 and 1000 AD, bear the inscription "+ULFBERH+T" or "+ULFBERHT+". Some of these Ulfberht swords were made of remarkably high-quality steel for their day. The steel had very few impurities (or slag), and unusually high carbon content, making it stronger, more flexible, and less brittle than most contemporary steel. Steel of this quality must be made in a crucible and requires much higher temperatures than European blacksmiths of the time were capable of producing at their forges; there is no evidence that Europeans could make crucible steel themselves until the Industrial Revolution 800 years later. Historians suggest that the Vikings made these swords from high-quality steel ingots from Central Asia which they acquired on the Volga trade route, which the Vikings are known to have used from the early-800s to the mid-1000s. However, there are no records of importing central Asian steel inguts and Ulfberht sword steel is different from the steel made in central Asia. Ulfberht swords do not have distinctive wavy pattern or extremely high carbon as other sword from that region. Allen Furrer duplicated a Ulfberht with bloomery steel like that of Viking age Europe and a clay furnace like that in Asia. No other weapons or armor made or used anywhere in Europe before the Industrial Revolution are known to have been made from this superior material. Ulfberht swords were truly exceptional.

The Ulfberht swords made from this crucible steel would have had superior performance in battle. They were extremely rare and valuable, and would have been prized possessions of the most elite Vikings. Historians suggest that the Ulfberht-inscribed swords that were not made from crucible steel were probably contemporary fakes, trading on the reputation of true Ulfberht swords.

The exact meaning or origin of the word Ulfberht is unclear. As these swords were made over a 200-year period, it is not possible they were all made by a single craftsman who was signing his work. The cross that appears twice in the inscriptions may be a reference to the Catholic church, as certain church officials of the time included such crosses in their signatures.