The case of Lady Darlington was different. It was assured generally that she, too, was a mistress of the King, a view that Lady Mary Wortley Montagu accepted, and one which was endorsed by the historians and biographers for more than a century. The first English writer to discover the truth was Carlyle, who in his Life of Frederick the Great said: “Miss Kielmansegg, Countess of Darlington, was, and is, believed by the gossiping English to have been a second simultaneous Mistress of His Majesty’s, but seems after all to have been his Half-Sister and nothing more.” She was, in fact, a daughter of the Countess of Platen (nee Clara Elizabeth von Meysenbach), not, indeed, by that lady’s husband, but by Ernest Augustus, Duke (afterwards Elector) of Hanover, the father of George I. Only Lady Cowper seems to have known this, and to have accepted it as a fact. Yet there was no secrecy concerning the paternity of the Countess, and it was, of course, well-known in the German Courts. Further, it was overlooked that in the patent of nobility in 1721 there is a reference to the royal blood of the recipient of the title, and actually the patent, in addition to the Great Seal, had a miniature of the King and the arms of the houses of Platen, Kielmansegg, and Great Britain (Brunswick-Lueneburg) with the bar-sinister.[2]
[Footnote 2: Refutation of the scandal is to be found in a work published in Hanover in 1902: “Briefe des Hertzogs Ernst August zu Braun schweig-Lueneburg an Johann Franz Diedrich von Wendt aus dem Jahren 1705 bis 1726,” edited by Erich Graf Kielmansegg.]