In "Les Trois Mousquetaires", we have a lot of sword fights. We have a dozen different people who are described as really good sword fighters. What sword schools were active during the 17th century in France? Do we still have fighting manuals from that period?
There are quite a few historic manuals linked from ARMA's page of manuals. The majority are pre-17th century, but there's a good dozen from that period.
As to schools, my understanding is that practically every fencing master would claim his/her own style.
As far as French manuals go, I know of only one from the late 16th century, entitled (deep breath):
Traicté contenant les secrets du premier livre sur l'espee seule, mere de toutes armes, qui sont espée dague, cappe, targue, bouclier, rondelle, l’espée deux mains & deux espées, avec ses pourtraictures, ayans les armes au poing por se deffendre & offencer à un mesme temps des coups qu’on peut tirer, tant en assillant qu’en deffendent, fort utile & profitable por adextrer la noblesse, & suposts de Mars: redigé par art, ordre & practique
The title is nearly longer than the book.
Essentially, it became a bit of a gentlemanly sport by the 17th century, leading to the development of the foil, and modern fencing is largely derived from the French school of sword work. Unfortunately, having done no fencing since high school, this is all I can recall.