Was this just language evolving over time or was it more of an intentional change for political reasons?
I've been doing a lot of reading on Rome and of course they alway referred to the region as Gaul. I know there were the Franks there as a group and I can only assume the name change to France had something to do with them but I'm afraid I have quite a huge gap in my knowledge here.
I was hoping someone here with more knowledge might be able to fill me in or point me to some sort of source I could check out on my own.
I would point you to Gregory of Tours' "History of the Franks".
A very brief overview is that the Franks, a Germanic group of people, invaded and eventually settled the Roman province of Gallic. There was a gradual shift in power as the Roman empire went into decline and the Franks grew in influence. By AD 509 Clovis was king over all the Franks with his capital in Paris, establishing the Merovingian dynasty that was named after his grandfather Merovech as the ruling family over Francia, where we get the name France. That dynasty would carry on for almost three hundred years, until the last Merovingian was removed in favor of a man named Pepin, Charlemagne’s father. Francia became many different things over the years. Especially due to the tradition of Frankish kings to split their kingdom between surviving sons, who would inevitably war with each other or sometime contrive to be the sole remaining heir. Of all the kingdoms the one name Francia would prove to be the most powerful and would eventually become the name of the nation we know today.
Gregory of Tours, History of the Franks: Books I-X, http://www.fordham.edu/halsall/basis/gregory-hist.asp
Wood, Ian, “The Merovingian Kingdoms, 450-751: A Reply,” French Historical Studies, Vol. 19, No.3 (Spring, 1996), pp. 779-784
Contreni, John J., “Introduction: The Merovingian Kingdoms, 450-751,” French Historical Studies, Vol. 19, No. 3 (Spring, 1996), pp. 755-756
hi! you might get something out of this FAQ section: it's really focusing more on the language transition but may be useful here