From Queen Charlotte’s page on wikipedia (whoever wrote it clearly did their homework!):
“Valdes y Cocom does not seem to take notice that the Vandals were a Germanic people originating from Northern Europe, that migrated first to Andalusia (modern southern Spain) in 409 AD, and afterwords to North Africa in 429 AD (namely to Numidia, were they established the Vandal Kingdom in North Africa), and that this poem is a eulogy linking Queen Charlotte to that distant Germanic nation, further straining the credulity of Charlotte’s supposed Sub-Saharan African ethnicity. However, the phrase Vandal race, used to describe Queen Charlotte, is linked with an official ducal title of the House of Mecklenburg: Princeps Vandalorum, . Prince of Wends, because of their overt Slavic origin.
All this has led Mario de Valdes y Cocom to inquire about her ancestry and research her genealogy. Still according to Valdes y Cocom, one of the possibilities for Queen Charlotte’s supposed racial features is that they were a concentration of traits inherited through three to six lines from a nine times removed ancestor of hers, Margarita de Castro e Souza, a 15th century Portuguese noblewoman who traced her ancestry six generations earlier to King Afonso III of Portugal and one of his lovers, Madragana.
Critics of this theory argue that Margarita’s and Madragana’s distant perch in the queen’s family tree, respectively 9 and 15 generations removed, makes any presumed African ancestry, Northern or sub-Saharan, negligible and no more significant in Charlotte than in any other member of any German royal house at that time, and therefore that Charlotte could hardly be accurately described as “mulatto” or “African”. Like everyone else, Charlotte had 32,768 ancestors in the 15th generation up her family tree, and she shared descent from Madragana with a large proportion of Europe’s royalty and nobility.
Even more, Valdez y Cocom assumed that Madragana was a Black African woman. In fact, a single author, Duarte Nunes de Leão, described her as a Moor, that is to say, in the context of the Iberian Reconquista, someone of Islamic religion, regardless of actual ethnic origin (and that could have been Arab, North African Berber, or Muladi – native Iberian European Christians who converted to Islam after the arrival of the Moors, all of whom can be described as Caucasian or White). Modern researchers, however, believe Madragana to have been a Mozarab, that is to say an Iberian Christian living under Muslim control, of Sephardi Jewish origin.
Valdez y Cocom has also argued, trying to defend the African origin of Queen Charlotte, that the Royal Household itself, at the time of Queen Elizabeth II’s coronation in 1952, referred to both her Asian and African bloodlines in an apologia it published defending her position as head of the Commonwealth. This is denied by Buckingham Palace.[48″