try to connect the names des Baux, de Baux, de Vaux, de Vallibus and Vance. *
They say that a Bertrand or Beraud de Baux came to Normandy in 929 or 939 CE, by invitation, to watch or participate in a tournament. None of them cite a source document (or maybe I'm just not seeing it or it's so obvious "everyone knows" and I'm looking right past it in my ignorance), but hopefully there is one, and maybe someone can post an extract of it, just a phrase and the source citation, out of some compilation or whatever.
A couple sites say that one Robert de Vallibus or de Vaux was a grand-son of the aforementioned Bertrand, while others just jump between.Others say the grand-son's name might have been Harold rather than Robert, and that he had 3 sons named Hubert, Robert and Rundolph. All 4 names recur in the various genealogies of both de Baux and Vance families, so there's a certain plausibility to the story.
Here's the difficult part.On the web pages dedicated to the des Baux/de Baux/de Balcio/de Balzo familes, they say that the earliest known was Pons/Pontius the younger/le jeune, born c. 950. d: c. 1030, and first documented 971-May-14 in a land grant, husband of Profecte/Profecta de Berre.
I see also Aiceline/Accelena de Baux (possibly daughter of Pons/Pontius de Baux iii?), 1st wife, d: before 1019, and Stephanie/Stephana de Baux-Rians, 2nd wife of William ii de Marseilla/Massiliensis who has a son Bertrand who died after 1045 April 13.
The earliest of the fairly-firmly connected de Vaux ones I see is John or Johannes in the 1200s at Dirleton.Above that, the ascendency gets a bit muddy.It may have been his father or great-grand-father Philip, who moved to Galloway, who was married to Elizabeth Comyn, daughter of William Comyn of Buchan and thus brought that designation along.
And then John/Johannes may have had a son named William, and daughter named Agatha who married a John Haliburton b: c. 1313 d: 1355 August at battle of Nisbet, and seemingly passing along the Dirleton title in their descendants.
* There are also a couple that, not surprisingly, connect Vaux with Fox and Welles. And one of the genealogy projects allow that both Vaux and Baux could have come from eastern Europe (northern Poland, or even possibly eastern Germany, Sloenia, or Austria) at one point.