Why were the franks a successful barbaric group?

Answer 1

The Franks expanded, rather than migrating, into the empire. Their numbers were constantly increased by men and women from old heartland of Frankish lands.

Answer 2

The Franks were successful because they were skilled warriors who adapted to Roman military tactics, had strong leadership, and formed alliances with other groups. They also effectively incorporated Roman political and administrative structures into their own society, allowing them to establish a powerful kingdom in the post-Roman era.