When this book was first published in April, 1900, I had no idea that it contained any of the elements of popularity. The subject which it treats had been of interest with me for years, and my researches were made from love of the work. In my quest I followed as closely as possible the footsteps of Sophie Dorothea during her life. I visited Celle where she was born, Hanover where she lived during her unhappy marriage, and Ahlden where for more than thirty years she was imprisoned. To Hanover I went again and again, and in connection with this book I also visited Berlin and Dresden. But it was not until six years ago, in 1897, that I lighted by chance (while turning over old volumes in a second-hand bookshop at Leipzig) upon the fact that an unpublished correspondence between Sophie Dorothea and Königsmarck existed. For a long time I could not find where these letters were deposited, and went in vain search to Upsala, but at last I learned that they were reposing in the library of the little university of Lund in Sweden. To Lund accordingly I went, and with the permission of the university authorities carefully examined the manuscripts. The result of my investigations is described at length in the chapter on “The History and Authenticity of the Letters”. It was the finding of these letters which determined me to write this book; it is built up around them. Even when the book was written I published it with misgiving, thinking it would have little interest for any except the few who love the untrodden paths and byeways of history. But, contrary to expectation, the book attracted a good deal of attention both in England and America. In France and Germany too it called forth comment, and in a short time several editions were exhausted, until at last it ran out of print. By that time I had learned something from my critics, more especially from those in Germany, and I determined not to issue another edition, until I had the opportunity of testing what I had written in the light of further historical research. I was then working at another book, _Caroline the Illustrious, Queen Consort of George II._, which also treats of the Hanoverian period, at a little later date, and until that book was finished, I had not the leisure to follow up fresh clues in connection with this one. Hence the publication of this revised edition has been delayed, for the book has been out of print some little time. Another consideration has also weighed with me, namely the fact, of which I was ignorant when the first edition was published, that a further instalment of the correspondence between Sophie Dorothea and Königsmarck is preserved in the Secret State Archives at Berlin. The letters herein are all from Lund, and found their way into Sweden through Amalie, Countess Lewenhaupt, Königsmarck’s sister, who married a Swedish nobleman and eventually settled in Sweden. But there are others.