How did the first royal families emerge in post Roman Europe?

by suoirucimalsi

For instance; the western roman empire ruled the french region until it fell to the visigoths. Sometime after this the region was ruled by a large number of noble families who answered to a few kings in a feudal system. Did these nobles claim descent from roman emperors, or was the nobility raised from important members of the population or military, or some other origin?

vertexoflife

Yes! Great question I want to know too. Follow-up, how did the nobility of the sword become established in France? Paging /u/idjet perhaps?

dreadnough7

Can anyone please recommend a few books that focus on this period of transition from the Western Empire's deathbed to the early Dark Age? Thank you.