*Ambirix as the Name Preserved in the Place-Name Amesbury

In the following recent blog post, I set forth Nikolai Tolstoy's new theory on a British origin for the 'Ambr' name found in Amesbury (Ambresbyrig):

http://mistshadows.blogspot.com/2018/06/ambiorixamborix-and-ambrosius-of.html

There were, however, linguistic problems stemming primarily from the /io/  in the personal name Ambiorix.  The other day I counter-proposed a spelling *Ambirix, based upon the presence in Gaulish of *ambi- names (as opposed to those showing *ambio-).  Dr. Simon Rodway's response was favorable:

"It is true that we have Ambigatus, Ambisagrus etc. in Gaulish, and these perhaps represent the original forms < ambi-, with Ambiorix representing a secondary development under the influence of compounds with io-stem nouns, e.g. Al (cf. names in ario-, cantio- in Gaulish and Brittonic) or containing another preverb like *wo-. Pierre-Yves Lambert (Etudes celtiques, 31 (1995), 115-21) favours the first explanation. If Lambert's argument about ambio- is right, then I think *Ambirix is theoretically possible."

Another Ambi- name is that of the coastal Belgic Ambiani tribe.  Coins was this tribe are found in southern Britain.  Dr. Simon Rodway was kind enough to pass along what Lambert has to same on this tribal name:

"He considers (pp. 116-17) the possibility that *ambio- might be a noun 'surrounding space'. If so Ambiorix would be 'king of the area' or perhaps 'king of the world' and Ambiani would be 'pertaining to the world', i.e. 'citizens of the world'? All this is offered very tentatively."

If Ambirix lies behind the English Ambr, then we did have here next at Amesbury the 'King of the [Round] Enclosure,' a very suitable name (or title?) for the ruler who presided over the hillfort of Vespasian's Camp near Stonehenge.