Finnish historical terminology entirely lacks the equivalent of the English "Dark Ages". I once got curious about this and asked a historian (my mother actually), who told me the period in question is simply either lumped under "Migration Period" or known by some more specific sub-category (à la "Viking Age") if appropriate. She explained that this was due to the simple fact in the British Isles the period following the Roman withdrawal pretty much, so far as is known, lived up to the term as things really were pretty harsh, chaotic, warlike and generally "dark" over there, but the Migrations themselves were pretty much over after the Angles and Saxons (the Viking settlers later on are a whole different story). On the continent, however, not only did the Migrations go on much longer - the last major one being the Hungarian-Magyars in the 900s - but also in many places things were also much less "dark", with reasonably strong and prosperous states which if nothing else were fairly able to defend their populaces. Certain regions - northern Italy springs to mind - were downright vibrant already this early on.