I am convinced that she may be advantageously employed in promoting your Majesty's service, and that it will be necessary to employ her, though I will not trust her further than is absolutely necessary." To these letters Louis replied on July 18: "There is no doubt that the Duchess of Kendal, having a great ascendancy over the King of Great Britain, and maintaining strict union with his ministers, must materially influence their principal resolutions.

You will neglect nothing to acquire a share of her confidence, from a conviction that nothing can be more conducive to my interests.

There is, however, a manner of giving additional value to the marks of confidence you bestow on her in private, by avoiding in public all appearances which might seem too pointed, by which means you will avoid falling into the inconvenience of being suspected by those who are not friendly to the Duchess, at the same time that a kind of mysteriousness in public on the subject of your confidence, will give rise to a firm belief of your having formed a friendship mutually sincere." 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.