The Barbarian World: The Coming of the Franks

During the Crisis of the Third Century, Roman texts mention a new group of barbarians arsing across the Rhine frontier--the Franks. These barbarian people would eventually go on to serve in Roman armies, fight against them, and ultimately would carve out their own kingdom after the destruction of the Western Roman Empire and the Kingdom of Soissons.
SOURCES:
Before France & Germany, Geary
The Roman Empire from Severus to Constantine, Southern
Framing the Early Middle Ages, Wickham