The title of Jean III de Grailly, Captal de Buch, seems odd to me. It was acquired by his father Jean II de Grailly (so it was passed down from father to son like other titles of nobility):
Jean III’s father, Jean II de Grailly, acquired the captalat of Buch (i.e., the principal seigniory in the land of Buch, the chief town of which was La Teste de Buch).
—http://www.britannica.com/EBchecked/topic/240795/Jean-III-de-Grailly-lord-de-Buch
It was apparently granted by Edward III:
And 'tis evident, this Knight of the Garter must be the Grandson of Peter, because we find that Edward III, in his thirty second Year, confirms to him, by the Title of Captal de Buch, the Lands that Peter his Grandfather (not his Father) held ..."
—The Register of the Most Noble Order of the Garter, Volume 2
It apparently derives from the Latin capitales domini, meaning "chief lords" (though I can find no other reference to this term):
Captal de Buch (later Buché) was an archaic feudal title in Gascony, captal from Latin capitalis "prime, chief" in the formula capitales domini or "principal lords."
The title was used by more than just the de Grailly family, but not many:
The title of "captal," which Jean de Grailly inherited in 1343, was used by only a few of the most prominent noble families of Gascony, such as the lords of Buch.
So the questions I have about the title captal:
- Why was de Grailly granted this title, which was apparently used by only a few families, and not some other title? Was it just some strange title invented on the spot because Edward couldn't or didn't want to use a more commonly-used title?
- Was Captal used in the same way as other titles, such as Duke or Viscount, where the title is used in place of the name? (E.g. "Who lead the charge?" "The captal did.")
- What was its order of precedence? Britannica says Jean I de Grailly was granted the "viscountcies of Benauges and Castillon" but Jean III is almost universally referred to by the captal title. Was Captal considered more prestigious or had the de Graillys lost all their other titles by the time of Jean III?
- What were the other families that used this title?
- Why did the title not outlive the Middle Ages as the titles of Duke and Count did?
- Was that title ever used outside of Gascony, or was it limited to Gascony as the Encyclopedia of the Hundred Years War above seems to imply?
- Why did the title derive from Latin rather than something in French? Did it have any connections with something used by the Romans?