Alexander Callander Murray’s scientific contributions

... The institutional backbone of a Scandinavian force was the warband. This is sometimes referered to as the comitatus or Gefolgschaft in studies dealing with the concept and the institution is traced back into the Roman Iron Age (Enright 1996). The concept of the warband is largely derived from literary and historical sources that are not contemporary with the Vendel Period, but from both before and after there are key concepts that remain constant. ...

Reference:

Faded Glory: Cultural exchange between warrior groups in the Vendel Period as reflected in armor from Vendel and Valsgärde