Anyone interested in some continental biography (which also impacts the ancestry of Prince Charles as well as the current king of Spain and queen of Denmark)?
According to Genealogics.org (
https://genealogics.org/getperson.php?personID=I00141098&tree=LEO) the wife of Botho VIII zu Eulenburg/Ileberg, who died 1480/1481, was a Margarethe von Berka von Duba und Lipa, who died about 1464 and was the daughter of Henryk/Heinrich/Jindrich von Berka von Duba und Lipa and his wife Anna zu Dohna. The source given for this is Gerald Paget's The Lineage and Ancestry of H.R.H. Prince Charles, Prince of Wales (Edinburgh: 1977), p. 1034.
I do not have Paget's work available to me (does it provide footnotes to primary sources?). What I do have available to me is the Diplomatarium Ilebergense, a two-volume (900+ pages in each volume) compilation of charters and other documents relating to the von Eulenburg (originally von Ileberg) family published 1877-79 by George Adalbert von Mülverstedt, who by that time already had nearly three decades of experience as an archivist in the Prussian state archives and as a published genealogist.
As far as I can tell, the relevant evidence is as follows:
1) Bothe von Ileburg, lord (Herr) of Sonnewalde (in what then was Lusatia and now is in the German state of Brandenburg), per charters dated August 1474 and January 1475 had adult sons named Otto, Botho, Wend, and Ernst (Mülverstedt, I: nr. 672, at
https://digital.ub.uni-duesseldorf.de/ihd/content/pageview/8342294, and I: nr. 812, at
https://digital.ub.uni-duesseldorf.de/ihd/content/pageview/8342414). At the sale of the lordship of Sonnewalde in October 1477 only Bothe von Eilburg and his sons Otte, Ernnst, and Wenth are named (Mülverstedt, I: nr. 677, at
https://digital.ub.uni-duesseldorf.de/ihd/content/pageview/8342297), suggesting that the son Botho had died in the meantime.
2) A membership register of the chivalric Order of the Swan (founded by Frederick II, elector of Brandenburg, in 1440 and open to women as well as men) that can be dated to 1464/65 (on the basis of who was listed as deceased and who as living) lists among the deceased "Margareta wife of the von Yleborch who lives at Sunnenwolde" (Mülverstedt, I: nr. 867, at
https://digital.ub.uni-duesseldorf.de/ihd/content/pageview/8342628; the full register can be found in S. Haenle, "Urkunden und Nachweise zur Geschichte des Schwanenordens," Jahresbericht des Historischen Vereins für Mittelfranken, 39 (1873/4): 1-178, with the relevant passage on p. 28, which is scan 74 at
https://opacplus.bsb-muenchen.de/title/3183817).
3) In 1510 Appolonia von Eyleborch, widow of Jorge Schencke von Tutenbergk, endowed a mass in Jüterbog (somewhat more than 30 miles northwest of Sonnewalde) for the souls of a number of people, including her parents Bate von Yleborch and his wife Margareta as well as Bate's sons Otte, Bate, Otte again, Waczelo, and Ernst (Mülverstedt, I: nr. 704, at
https://digital.ub.uni-duesseldorf.de/ihd/content/pageview/8342322). If Waczelo is seen as a version of Wend/Wenth (which is likely a short form of the German Wenzel or Czech Vaclav), and the second Otto was a son who died in infancy, then this series of sons is the same as that mentioned for Bothe von Ileburg, lord of Sonnewalde, in the charters of 1474 and 1475. This identification is strengthened by the fact that Appolonia's husband, Jorge Schencke zcu Thuthenbergk, in a 1476 letter named the Botthe von Ilburg who was lord of Sonnewalde as his father-in-law (Mülverstedt, I: nr. 822, at
https://digital.ub.uni-duesseldorf.de/ihd/content/pageview/8342424). It is noteworthy that the mass was also endowed for the soul of an Albergk Berken (no relationship stated).
4) In the abbey church of Mühlberg/Elbe (a foundation of the von Eulenburg family located about 25 miles southwest of Sonnewalde) there was still preserved in the 1870s a gravestone for a Bothe von Eyleborgk who had died in spring 1476 (sketch at Mülverstedt, I: illustration 3, at
https://digital.ub.uni-duesseldorf.de/ihd/content/pageview/8342724; discussion at Mülverstedt, I: nr. 674, at
https://digital.ub.uni-duesseldorf.de/ihd/content/pageview/8342296, and at Mülverstedt, I: pp. 685-688, at
https://digital.ub.uni-duesseldorf.de/ihd/content/pageview/8342556). This almost certainly was the younger Botho, who was mentioned as a son of our Botho lord of Sonnewalde in 1474 and 1475 but not in 1477. The gravestone features the coat of arms of the von Eulenburgs prominently in the center. There are four other coats of arms in the corners of the gravestone. The one in the upper left corner features a six-pointed star; this is the coat of arms of (among others) the family von Hakeborn (see
https://de.wikipedia.org/wiki/Hakeborn_(Adelsgeschlecht)), likely the family of our Botho's mother and thus the deceased's paternal grandmother (in a 1436 letter our Botho had called a Hans von Hackenborn his uncle, see Mülverstedt, I: nr. 516, at
https://digital.ub.uni-duesseldorf.de/ihd/content/pageview/8342210). The coat of arms in the lower left corner (which, according to Mülverstedt, was the normal place for the coat of arms of the deceased's mother) features two crossed tree branches that have been stripped of twigs and leaves; this is clearly the coat of arms of the family Berka von Dubá / Berkové z Dubé (see
https://de.wikipedia.org/wiki/Berka_von_Dub%C3%A1). The coat of arms in the upper right corner is rather indistinct in the sketch, but with some imagination could be interpreted as two crossed five-pointed deer antlers, which is the coat-of-arms of the family von Dohna (see
https://de.wikipedia.org/wiki/Dohna_(Adelsgeschlecht)). Finally, the coat of arms in the lower right corner feature a rising goat over a field of vertical bars, this appears to be the coat of arms of the von Kittlitz family (see
https://de.wikipedia.org/wiki/Kittlitz_(Adelsgeschlecht))
On the basis of evidences (2) and (3) above, it appears clear that Botho's wife (and very likely the mother of his children) was named Margaretha. On the basis of evidence (4), and specifically the coat-of-arms in the lower left corner of the grave stone, Mülverstedt concluded that she was a member of the family Berka von Dubá. But he did not go any further in speculating on her parentage.
The presence of the von Dohna coat of arms on the same gravestone as the Berka von Dubá coat of arms suggests that Margaretha's mother might have been a von Dohna, and the mention of an Albert Berken (i.e., Berka) among those for whom her daughter endowed a mass in 1510 suggests that Margaretha's father might have been named Albert or Albrecht (back then these names were equivalent in German). There indeed was an Albrecht (not Heinrich/Jindrich, as suggested in Genealogics.org) Berka von Dubá (died 1471), lord of Wildenstein (on the Saxon-Bohemian border about 60 miles south-southeast of Sonnenwalde), whose wife Anna (died 1449) was the daughter of a Wentsch von Dohna, lord of Grafenstein (today's Grabštejn nearly 30 miles east of Wildenstein). This Albrecht Berka together with his father-in-law was involved in numerous feuds with cities in Upper Lusatia in the 1440s until falling out with Wentsch von Dohna after Anna's death (see Robert Lahmer, Chronik der Stadt Schluckenau (Schluckenau: 1889), pp. 27-29, at
https://archive.org/stream/chronikderstadt00lahmgoog#page/n50/mode/2up). Thus, it is at least possible that this Albrecht Berka and his wife Anna von Dohna were the parents of Margaretha, wife of Botho von Eulenburg. However, as far as I can tell Mülverstedt's compilation features no documents in which our Botho appears together with this Albrecht Berka von Dubá.
Does anyone on the list have any further evidence that might support the reconstruction shown at Genealogics.org?