In a discussion on SGM, Peter Stewart provided evidence for the identity and family of Renaud de Courtenay's wife. Some sources suggest that her given name was Maencia but provide contradictory claims about the identity of her family. [1]
I have just finally twigged that Estournet was misled about the family of Elisabeth's mother from his acceptance of the old false notion that St William's uncle was named Guillaume instead of Pierre l'Hermite.
As posted above, the maternal uncle to whom the young St William was sent to be educated was explicitly named in one medieval source as Peter the Hermit, archdeacon of Soissons ("Beatus Guillermus ... avunculo suo Suessionensis ecclesiæ archidiacono ... qui Petrus Eremita dicebatur a parentibus traditus fuit moribus et litteris informandus"). However, a passage in another Vita has been misinterpreted to make him instead a namesake of his saintly nephew, whereas the William deserving the byname Hermit is actually the nephew himself ("Beatus Willelmus ... traditus ad erudiendum et educandum suo avunculo archidiacono Suessionis ecclesiæ, qui Eremita cognomine vocabatur, quia mores in simplicitate a convictu formavit meruit Willelmus Eremita vocari").
In the course of the 12th century there were two archdeacons of Soissons named Peter and one named William. Only one of these, the second, fits the chronology required, as he was in office from 1155 (around the time St William was probably born) until 1180, and he was definitely known as Peter the Hermit. The earlier Peter (in office 1095-1125) was son of Guy I of Châtillon and Ermengarde of Choisy or Coucy, and was allegedly born blind but given sight by applying the saliva of St Arnulf, bishop of Soissons to his eyes. He was far too early to have raised St William of Bourges. The archdeacon named William was not known as "the Hermit" and he occurs only in the mid-1140s, before the time St William could have been born as his mother was then married to Renaud de Courtenay.
This leaves the archdeacon named in several charters and other sources as Peter the Hermit, in office from 1155. Luckily we know his family, and it was neither that of the seigneurs of Arthel or the viscounts of Clamecy as proposed by Estournet. William Mendel Newman in *Les seigneurs de Nesle en Picardie* (1971) vol. 1 p. 116 note 15 showed that Peter was a brother of Guy (IV according to Newman) le Bouteiller of Senlis, butler to Louis VII (died 1188, husband of Marguerite of Clermont). It makes perfect sense that Louis would have married his brother Pierre to a niece of this courtier.
Newman quoted a charter of Guy dated to 1180/87: "ego Guido, regis Francorum buticularius ... pro anima fratris mei Petri Heremite, Suessionensis prepositi et archidiaconi" (I Guy, the king of France's butler ... for the soul of my brother Peter the Hermit, provost and archdeacon of Soissons). The reference given for this is "Coll. Picardie, 258, f. 143, Église de Senlis". Unfortunately, this volume of the Dom Grenier collection does not seem to have been digitised yet, though the concordance between BnF catalogue details and the titles used on Gallica is (to put it politely) Gallic.
The naming of St William's - and consequently Elisabeth de Courtenay's - mother as Maencia and linking her to Arthel in the Nivernais where he is said to have been born are not sufficent evidence to rely on as much as Estournet did, since this information can be traced back no further than the mid-16th century. The name M(a)encia would be odd in the family of
the Bouteillers of Senlis, but that alone does not rule it out. Her confinement at Arthel would be a puzzle too, if certain, but not enough to counter the clear evidence provided by newman for the family of her brother Peter the Hermit.… the mother of "Maencia" of Senlis was named Adelina and Adelvia in different sources, just like her second Courtenay daughter.
Maencia's aunt (or cousin) and then her sister Clementia were the first two abbesses of Yerres abbey, so there is no great mystery about her marrying the seigneur of Yerres. Their brother Pierre was placed into the Bouteiller de Senlis family by Du Chesne in manuscript, repeated in print by Père Anselme, but no-one (including myself) bothered to find out exactly why and that this was indeed Peter the Hermit until William Mendel Newman published proof (without realising the Elisabeth de Courtenay implication) in 1971.
The main red herring that prevented so many from realising Maencia belonged to the Bouteiller de Senlis family was the misreading of St William's Vita about precisely who deserved the byname "Hermit". One French historian in the mid-19th century actually asserted that the identification of St William's uncle as Peter rather than William was a gross error, yet the right understanding about this had been placed on record by no less than the great Cistercian historian Crisóstomo Henríquez as long ago as 1623.
[1] Newsgroup Post, soc.genealogy.medieval, multiple posts by Peter Stewart in the thread "Parents of Elisabeth de Courtenay" dated November 6-18, 2019, [GoogleGroups_SGM].