Just side issues.
1. Occitan was a "big" language in the middle ages. Dante obviously read works written in it. Richard Lionheart is said to have written in it when in prison in Austria.
2. Concerning French placenames, I have recently been doing a lot of work on Anglo-Normans, and while I generally leave birth and death places empty unless there is real evidence I have been editing the traditional citations of probable places of origin in Normandy. The standard work everyone follows (including Keats-Rohan and Complete Peerage) is Loyd, who wrote in 1951, when it seems there was very little English feeling for modern French abbreviations. (For example he abbreviates kilometres as kil.) He uses modern French placenames, but gives a complex of département, arrondisement, canton. I suppose he had, and assumed other people had, some type of printed directory or atlas. Unfortunately, it is easy to see many people trying to use these get confused and would not be able to find these places on a map, so when it is important I've been doing what I do when looking for a place in France: giving modern postcodes for the commune in brackets. These work much better on Google and Wikipedia.