Quoting: Casimir
Witek, there were always slavs there
Kazek,
Slavs emerged from obscurity when the westward movement of Germans and Celts in the 5th and 6th centuries AD started the great migration of the Slavs, who settled the lands abandoned by Germanic tribes fleeing the Huns and their allies: westward into the country between the Oder and the Elbe-Saale line; southward into Bohemia, Moravia, much of present day Austria, the Pannonian plain and the Balkans; and northward along the upper Dnieper river.