I believe I have finally settled on the book that I will take on my road trip. Rather than go with any of the ones I was considering earlier, I have instead chosen The History of the Franks by Gregory of Tours (539AD-594AD). Tonight I started reading the Penguin Classics edition translated by Lewis Thorpe and right away knew that this would be the best pick. I had been really tempted to go with The Book of Contemplation but I didn't feel as if I had enough of a contextual understanding of the times to get as much out of the book as I would want. Nor am I planning on painting anything from the Crusades period for the foreseeable future so I therefore don't really feel like diving into that period just yet. I do like the idea though of reading some original source material though instead of one of my contemporary's analysis so that Gregory's work nicely fits that criterion.
After I move on from the Hundred Years War portion of the medieval period, I am pretty sure I want to next focus my attention on the so-called European Dark Ages and in particular the wars fought between the Franks and the Arabs for control of Spain. (Makes sense considering the number of Carolingians and Andalusians I purchased in the last couple of weeks.) As I said before, though, I am only very superficially familiar with not just this period but also much of the time preceding it as well. I believe therefore that Gregory's history should be a good reference for that transitional period from the end of effective Roman control to the later portion of Merovingian rule. Even though this is earlier than time in which I have expressed my main interest, it should nonetheless provide an excellent foundation for my understanding of the later Carolingian renaissance. Also it serves to keep the other books I have fresh for when I am actually ready to start painting the relevant armies.
So much thought and consideration has gone into the choice, I really hope the good Bishop does not let me down. But just in case I'm take Longitude as a back up.