swords of the 8th to 12th centuries found within the boundaries of East Francia (as such including the transitional types between the "Viking" and the "knightly" sword). Oakeshott (1991): Mainly dealing with sword from the post Viking-age period. He classifies all of the Viking Age swords as his type X. Jakobsson (1992): has recently published a number of maps detailing the distribution patterns of Petersen's sword hilts across Europe. Jokobsson's conclusions are discussed in Ian Peirce's 'Swords from the Viking Age' Peirce (2002): Oakeshott provides an overview of typologies and a discussion on inscribed blades. Jones also provides an overview of hilt and blade classifications, provides a summary of Jakobsson's and Geibig's work and provides an updated typology date range chart. Peirce provides a catalogue of examples, detailing 85 complete or almost complete swords and comparing them to Petersen's discoveries. Metallurgy An important aspect in the development of the European sword between the early and high medieval periods is the availability of high-quality steel. Migration period as well as early medieval sword blades were primarily produced by the technique of pattern welding, also known as "false Damascus" steel. Blooms of high-quality steel large enough to produce an entire sword blade were only rarely available in Europe at the time, mostly via import from Central Asia, where a crucible steel industry began to establish itself from c. the 8th century. Higher quality swords made after AD 1000 are increasingly likely to have crucible steel blades. The group of Ulfberht swords includes a wide spectrum of steel and production method. One example from a 10th-century grave in Nemilany, Moravia, has a pattern-welded core with welded-on hardened cutting edges. Another example appears to have been made from high-quality hypoeutectoid steel possibly imported from Central Asia. Notable examples The Sæbø sword, a 9th-century type C sword found in 1825 in a barrow at Sæbø, Vikøyri, in Norway's Sogn region. The sword is notable for its blade inscription, which has been interpreted as runic by George Stephens (1867), which would be very exceptional; while Viking Age sword hilts were sometimes incised with runes, inlaid blade inscriptions are, with this possible exception, invariably in the Latin alphabet. One of the heaviest and longest extant swords of the Viking Age is dated to the 9th century and was found in Flå, now kept at Museum of Cultural History, Oslo, at a total length of 102.4 cm and