G.P.R. James 
Arabella Stuart: A Romance from English History [EPUB ebook] 

This is a romantic fiction that purports to be a biography of Arabella Stuart of the Stuart royal line that ruled Great Britain. From the foreword:

“In depicting the characters of the various persons who appear upon the scene, however, I have had a more difficult task to perform, being most anxious to represent them as they really were, and not on any account to distort and caricature them. The rudeness of the age, –the violent passions that were called into action, –the bold and erratic disregard which thus reigned of all those principles which have now been universally recognised for many years, rendered it not easy to give the appearance of truth and reality to events that did actually happen, and to personages who have indeed existed; for to the age of James I. may well be applied the often repeated maxim, that ‘Truth is stranger than Fiction.’

Difficulties as great, and many others of a different description, have been overcome in the extraordinary romance called ‘Ferrers;’ but it is not every one who possesses the powers of vigorous delineation which have been displayed by the Author of that remarkable work; and I have been obliged to trust to the reader’s knowledge of history, to justify me in the representation which I have given of characters and scenes, which might seem overstrained and unnatural, to those who have been only accustomed to travel over the railroad level of modern civilization.

The character of James I. himself has been portrayed by Sir Walter Scott with skill to which I can in no degree pretend–but with a very lenient hand. He here appears under a more repulsive aspect, as a cold, brutal, vain, frivolous tyrant. Nevertheless, every act which I have attributed to him blackens the page of history, with many others, even more dark and foul, which I have not found necessary to introduce. Indeed, I would not even add one deed which appeared to me in the least degree doubtful; for I do believe that we have no right to charge the memory of the dead with anything that is not absolutely proved against them. We must remember, that we try them in a court where they cannot plead, before a jury chosen by ourselves, and pronounce a sentence against which they can make no appeal: and I should be as unwilling to add to the load of guilt which weighs down the reputation of a bad man, as to detract from the high fame and honour of a great and good one. My conviction, however, is unalterable, that James I. was at once one of the most cruel tyrants, and one of the most disgusting men, that ever sat upon a throne.

In the account I have given of Lady Essex, I shall probably be accused of having drawn an incarnate fiend; but I reply, that I have not done it. Her character is traced in the same colours by the hand of History. Fortunately, it so happens that few have ever been like her; for wickedness is generally a plant of slow growth, and we rarely find that extreme youth is totally devoid of virtues, though it may be stained with many vices. Such as I have found her, so have I painted her; suppressing, indeed, many traits and many actions which were unfit for the eye of a part, at least, of my readers. Dark as her character was, however, its introduction into this tale afforded me a great advantage, by the contrast it presented to that of Arabella Stuart herself; bringing out the brightness of that sweet lady’s mind, and the gentleness of her heart, in high relief; and I hope and trust, tending to impress upon the minds of those who peruse these pages, the excellence of virtue and the deformity of vice.”