ANTOR, FOSTER-FATHER OF ARTHUR, AND ALDROENUS/ALDWR/AUDROENUS

The identity of the 'Antor' introduced by Robert de Boron as the foster-father of Arthur has remained elusive.  The two primary theories are that either Antor is merely a corruption of the name Arthur or that it is a corruption of the Latin word auctor.  

When looking for Antor, it is important to remember what we are told in Layamon/Lawman, i.e. that upon Uther's death, Arthur is sent for from Brittany.  This point is often missed, unfortunately.

Now, I think there is a rather elegant solution to the problem of just who exactly Antor might be.  There is good evidence that the Arthurian hero Cei/Cai, the later Kay, was confused in story with St. Kea of Cornwall and Brittany.  For those interested in the details of how this happened, do consult https://www.jstor.org/stable/1260322.  

When I looked at the St. Kea localities, I noticed that two were in Cotes-d'Armor.  Also in Cote-d'Armor is Chatelaudren, a place that quite probably preserves the name of Geoffrey of Monmouth's Aldroenus.  The Welsh called this man Aldwr, and his name is found spelled in some early souces as Audroenus.  As u and n are often interchangeable in MSS., and /dro/ and /dor/ can occur due to simple metathesis, I have no problem, personally, with Antor being a corruption of Aldroenus/Aldwr/Audroenus.  

The following on Welsh Aldwr, etc., is from Bartrum's A CLASSICAL WELSH DICTIONARY:

ALDWR (Aldroenus). (Fictitious). (415)According to HRB VI.4 Aldroenus was a king of Armorica, the fourth from Conan Meriadoc, to whom Guetelinus, Bishop of London, came, offering him the kingdom of Britain if he would aid in repelling the Picts and Scots. Aldroenus declined the offer but sent his brother, Constantinus (see Custennin Fendigaid). In Brut y Brenhinedd the name becomes Aldwr. Being the brother of CustenninFendigaid he was given the same pedigree, that is, Aldwr brenin Llydaw ap Kynfor ap Tudwal, etc.(Peniarth MS.181 p.58, mid 16th century). Compare MG 5, ByA 30 in EWGT pp.39, 93.The old Breton historians accepted HRB for the fictitious early kings of Armorica. The ‘Chronicle of St.Brieuc’ calls him Audroenus. Iste fecit castrum Audroeni prope Guingampum. (Dom PierreHyacinthe Morice, Mémoires pour servir de Preuves ... Vol.I, Paris, 1742, Col.9 - 10). Châtelaudren is a small village between St.Brieuc and Guingamp in north Brittany. It seems that Geoffrey of Monmouth had a Breton source for his name Aldroenus.

More on Aldroenus can be found at http://christophergwinn.com/arthuriana/arthurs-pedigree/:

...that Aldroen (Old Breton Altroen) son of Salomon was accepted as a 5th century king of Brittany by late medieval and early modern Breton historians (Salomon is stated to have reigned after Grallon [or vice-versa], who succeeded Conan Meriadoc), but sources mentioning him prior to Geoffrey’s HRB are lacking. In later Breton histories he is stated to be the eponymous founder of the Breton town of Châtelaudren, former capital of the province Goello (in the Chronicon Briocense we read “Audroenus rex quartus a Conano fuit; iste fecit castrum Audroeni prope Guingampum”; the town is called called Castellum Audroeni in a charter dating to 1148 concerning the church of Saint Mary of Lanleff and Castrum Audrini in a charter from 1181; the fortress’ foundation dates to the 11th century). In a charter concerning Ploucasnou (OBr Ploicathnou) dating to 1061 and ascribed to Bertha de Blois (daughter of Odo II Count of Blois and wife of Alan III Duke of Brittany) and her son Conan II Duke of Brittany (brother of Hawise Duchess of Brittany, wife of Hoel II Duke of Brittany, who were the parents of Alan IV Fergant Duke of Brittany), mention is made of a witness named Pontius (or Poncius) son of Aldro(e)nus; he is likely the same person as Eudo Pontius, mentioned in the Lanleff charter above in connection with Castellum Audroeni. André-Yves Bourgès suggests that Castellum Audroeni could be named after Eudo Pontius’ father Aldro(e)nus.

Green has attempted to make much of a connection between an Aladur mentioned in early Welsh poetry and a god Alator:

https://www.academia.edu/27372860/A_Note_on_Aladur_Alator_and_Arthur

I have suggested, instead, that Aladur is simply for Aldwr (with an intrusive /a/):

https://mistshadows.blogspot.com/2019/04/arthur-and-god-alator-of-south-shields.html

IT IS IMPORTANT TO NOTE THAT ALDROENUS DOES NOT APPEAR IN ROBERT DE BORON, NOR IS HE TO BE FOUND IN THE VULGATE.  After Geoffrey of Monmouth, he seems to disappear.  Thus what Robert did was to remove Aldroenus from his role in Geoffrey, and use him in a fashion similar to how that author employed Budicius of Brittany as fosterer of Uther and Ambrosius.