Ulfbert swords, also known as Ulfbert swords, are the collective name for more than 170 examples of medieval swords dating between the 9th and 11th centuries. They are distinguished by the high quality of workmanship for Western Europe in the early Middle Ages, as well as the mass and uniformity of the + VLFBERHT + marks on the blade.
The sword is of the Carolingian type, straight, double-edged, usually with a short straight guard. Most are of type X according to Oakeshott's typology. Most have a geometric pattern in addition to the lettering. It is noteworthy that the latest of the dated "Ulfberts", in addition to the usual stamp, has the inscription "In the Name of the Lord" ("in nomine domini", + IINIOMINEDMN in the original [4]). The main external indicator of this type of blade is the stamp + VLFBERHT +, made with iron, and more often with unmasked wire, hot inlaid in the upper third of the blade on both sides of the blade.
The inscription is made in Latin capital script and was located in the upper third of the sword's fulcrum. Usually its length was 14-16 cm. In the finished form of the sword, the inscription stood out brightly against the background of the blade. A large volume of red copper and brass wire was wound on the surface of the pommel and crosshairs, often with the inclusion of silver stripes. As a result, the handle shimmered in the light, giving the weapon a "shimmery" look.
Unlike modern European swords of this type, made according to the "false Damascus" technology, "Ulfbert" is made of crucible steel with a high carbon content - up to 1.2%. There are frequent finds of this type of swords with an uncharacteristic pattern covering the hilt and guard, which probably indicates the export of blades to third countries.
Although most Ulfberts are found in Northern Europe, their region of origin appears to be Austrasia. Due to the shape of the name "Ulfberht", it was assumed for a long time that the swords were of Frankish origin, but the blade found in Lower Saxony in 2012 had lead mined in the Taunus region, which strengthened the hypothesis of the Frankish theory of the origin of the protomanufactory "Ulfbert". From there, swords were sold throughout Europe, up to the Volga Bulgaria. As of 1997, 20 similar swords were found on the territory of the modern Russian Federation and Ukraine. Most of them were found in Scandinavia, which is to some extent explained by the pagan Scandinavian funeral rite, in which the owner's sword often played an important role. According to the theory of A. N. Kirpichnikov, swords were exported in batches,and were sold to professional soldiers, for example, the Normans.
According to a number of researchers, the name "Ulfbert", which originally belonged to a blacksmith-master, was eventually assigned to a mass product, which was produced by several generations of blacksmiths of his family. A number of imitations are also known, with inscriptions made in a similar style. They are generally identified by their lower carbon content, in the range of 0.5-0.7%. However, there are imitations of extremely high quality by the standards of Medieval Europe, for example, the pseudo-"Ulfbert" from a private collection with a hardness of up to 450 units according to Vickers, made of steel with a carbon content of up to 1%. In the 1990s, a group of researchers, which included, in particular, A. Stalsberg and A. N. Kirpichnikov, conducted research into the funds of Scandinavian museums. As a result of a comprehensive study using stereo photography,X-ray and other methods were able to identify 47 more previously unknown swords with previously unrecognized brand marks "Ulfbert" in addition to 132 previously known.
The carbon content in all samples is non-uniform and varies within 0.7-1.2%, depending on the sample and the investigated part. The hardness of the edge of the blade reaches 470 units according to Vickers, but closer to the core it drops to 355. There are also specimens with defects, whose hardness reaches only 256 units, according to Alan Williams, in these cases overheating of the workpiece is likely due to a blacksmith's mistake or forgery. Unusual for Europe technology leads some researchers to believe the imported origin of the metal for the "Ulfberts", possibly - Persia or India.