This practice distinguished the elites and affirmed their social status. Similar graves, which are usually isolated, have been discovered in Northern Gaul, Germany and eastern Europe. They are accompanied by abundant grave goods. They thus appear to be the graves of high dignitaries and their families, of eastern origin, incorporated into the Roman army during the “great migrations”. The Obernai necropolis is one of the few large groups of discovered in France. It is the first evidence of the presence of an eastern community over a long period of time in Alsace at the end of the Roman Empire.
I've blogged about these skulls before - here and here ... - but the Merovingian connection makes this one interesting ... and reminds us that they, like the Carolingians that came after them, emerged from a Germanic milieu. To my knowledge none of the French royal tombs at St Denis or elsewhere have deformed skulls.