Did the Viking Age start during the Roman period or was it after?

There are always going to be problems when trying to neatly tie off history into ages and periods. Take the "Roman Period" for example, when do we mark it off? 753 BC - 476AD? But what about the Eastern Romans, do we mark them off as separate? What about their end date, should we use 1204 or 1453, or even 1923 when the last person to claim sovereignty over "the Romans" was deposed? The issue with the Vikings is no less complex, in the Anglo-phone world the "viking age" is traditionally marked as 794 to 1066, the raid on Lindisfarne to the defeat of Harald Hardrade at Stamford Bridge, but what do we do about the Danish attacks on England subsequently? What about the shift in Scandinavian orientation from Britain to the Baltic? Is that enough to constitute the change in an age?

I'm not saying all of this to be merely pedantic, these are debates that are ongoing and affect a great deal of what history gets paired with what. A classics department for example would likely balk at the idea of incorporating discussions about the vikings in their classes, despite the overlap of several centuries from the first raid on Britain to the collapse of Eastern Roman Empire. (They might also balk at the idea of including the Eastern Romans admittedly)

Really this all depends on where you draw the lines on the historical calendar. What can be said with some certainty is that the high period of viking activity in Europe, think the Micel Here arriving in England, the conquest of England by Svein and again under Canute, and the raids on Paris all occurred roughly within two hundred years of each other, and at this time the people identifying themselves as Romans were also very much active, with wars going on in Sicily, Southern Italy, and the Levant, attacks by the Viking derived Rus, and even the establishment of the Varangian Guard, we just happen to call these Romans Byzantines in the West.