Information about the earliest stages of the Old Scandinavian period is derived from runic inscriptions, which became more abundant after the creation of the short runic futhark about AD 800.
The expansion of Nordic peoples in the Viking Age (c. 750-1050) led to the establishment of Scandinavian speech in Iceland, Greenland, the Faroe Islands, the Shetland Islands, the Orkney Islands, the Hebrides, and the Isle of Man, as well as parts of Ireland, Scotland, England, France (Normandy), and Russia. Scandinavian languages later disappeared in all these territories except the Faroes and Iceland through absorption or extinction of the Scandinavian-speaking population.
During the period of expansion, all Scandinavians could communicate without difficulty and thought of their language as one (sometimes called "Danish" in opposition to "German"), but the differing orientations of the various kingdoms in the Viking Age led to a number of dialectal differences.
It is possible to distinguish a more conservative West Scandinavian (C.f. Old Norse) area from a more innovative East Scandinavian (C.f. Runic Swedish).