Regrettably it's true: there are zero general interest history books in English about medieval Provence. In fact, there aren't generalist histories of medieval Occitania in English either.

In the high middle ages, Provence sat in a peculiar nexus of competing political interests: the Holy Roman Empire and Italian nobility, the counts of Barcelona/king of Aragon, the Counts of Toulouse and the King of France. This environment created the context for Avignon becoming the home of the papacy for a while in the 14th century (the so-called Babylonian exile). Below is a useful summary of the medieval Provencal-Languedocian history from the introduction to this book of diverse essays:

• Reyerson, Kathryn Louise, and John Victor Drendel Urban and Rural Communities in Medieval France: Provence and Languedoc, 1000-1500 (Brill, 1998)

Languedoc came within the domination of the king of France in the thirteenth century as result of the Albigensian crusade that sent northern French knights of the Ile-de-France to the south, first under Simon de Montfort, who was killed at Toulouse in 1281, and then under the prince Louis, who would become Louis VIII of France at the death of his father, the great king Philip Augustus, in 1223. Together these provinces present a large territory, almost synonymous with the boundaries of language (langue d'oil/langue d'oc) and law (oral/customary law versus written/Roman law) separating the north and the south of France. However, medieval Provence was under the domination, not of France but of the German empire in the eleventh and twelfth centuries, and then of the Angevin kings in the thirteenth through fifteenth centuries. Provence would only become French under King Louis XI in 1482. There were, moreover, some few political enclaves in the midi, such as the lordship of Montpellier, which came under French control late, in 1349. Political fragmentation aside, this was a relatively unified cultural zone; in the twelfth century there was a possibility that the south of France might be united in a middle kingdom with northern Spain and northern Italy under such rulers as the counts of Toulouse-Saint-Gilles or Barcelona-Provence.

There are a few specialized histories of the domains of the counts of Toulouse-Saint-Gilles, and the kingdoms of Barcelona and Aragon. For my money, the best work in English which covers a good part of Occitan history (in microcosm) is also the most readable:

• Cheyette, Fredric L. Ermengard of Narbonne and the World of the Troubadours (Cornell University Press, 2001)

It's a fantastically rich book, however it does stop at the 13th century, and it is focused on the Languedoc shores stretching from Barcelona to Montpellier. However, the Barcelona families intermarried heavily into the Provencal nobility and it does touch that fascinating history. As well, the Narbonne nobility did a tremendous amount of interchange with mediterranean traders and were at the intersection of important commercial and military ventures.

An alternate path in reading is to study up on the aforementioned Avignon Papacy of the 14th century. The choice of Avignon by the papacy can tell you a lot about the political alignment and history of Provence in the prior centuries. Despite it's age, this book is still a recommended high-level general history that you can find really cheap used copies online:

• Renouard, Yves. The Avignon Papacy, 1305-1403 (Archon Books, 1970)

Please let me know if you want to explore Occitania more, or other related interests, and I can make some more recommendations.