Even Julius Caesar held the Gauls in contempt.
At the time we are speaking of - 12th century,
the following had already occurred:
From around 395 onwards the Goths, Vandals, and Burgundians, Germanic peoples who had long inhabited the area east of the Rhine, came under pressure from invasions of nomadic peoples from further east, and began to migrate westwards over the Rhine. The Burgundians were the first to settle, and they founded a kingdom that stretched down the Rhine valley from the Vosges to the sea (see Burgundy (ancient)). The Vandals founded a Visigothic kingdom in Spain, a kingdom that also stretched into southwest France. In 451, at the great battle of the Catalaunian Fields, Aëtius, the last of the Roman generals in Gaul, defeated the Huns of Attila.
The most important of the ‘barbarian’ invaders of Gaul was Clovis I, the king of the Franks (481–511). The Franks were a Germanic tribe who had lived in what is now Belgium (the Salian Franks) and on the banks of the rivers Sambre and the Meuse (the Ripuarian Franks). United by Clovis, the Franks invaded Gaul and quickly overran it, advancing rapidly towards Paris, which they made their capital.
http://encyclopedia.farlex.com/France:+history+to+1515 Though there is much more to the tale, before the 12th century, it is from that point, from "the Franks", that the nation and the people took and retained their name - France. By then the Gauls were a long-ago over-run minor remnant strain in the make-up of the people.