No wonder that the history of this illustrious couple has formed, and still forms, the theme both of laborious scientific researches and of poetical compositions. Amongst the latter we may here mention in passing a well-known novel by Rousseau de la Valette,[01] because it has had the undeserved honour of being treated by a modern writer as an historical source, to the great detriment of his composition. Documents which have originated from these two personages are of course of great value. Besides letters and public documents, there exist several accounts written by both Corfits Ulfeldt and Leonora referring to their own life and actions. Ulfeldt published in 1652 a defence of his political conduct, and composed, shortly before his death, another, commonly called the 'Apology of Ulfeldt,' which has not yet been printed entirely, but of which an extract was published in 1695 in the supplement of the English edition of Rousseau de la Valette's book. Some extracts from an incomplete copy discovered by Count Waldstein in 1870, in the family archives at the Castle of Palota, were published with the German edition of Leonora's Memoir; complete copies exist in Copenhagen and elsewhere. Leonora Christina, who was an accomplished writer, has composed at least four partial accounts of her own life. One of them, referring to a journey in 1656, to be mentioned hereafter, has been printed long ago; of another, which treated of her and Ulfeldt's imprisonment at Bornholm, no copy has yet been discovered. The third is her Autobiography, carried down to 1673, of which an English version follows this Introduction; it was written in the Blue Tower, in the form of a letter to the Danish antiquarian, Otto Sperling, jun., who wished to make use of it for his work, 'De feminis doctis.'[02] [01] _Le Comte d'Ulfeld, Grand Maistre de Danemarc._ _Nouvelle historique_, i.-ii. Paris, 1678. 8vo. An English translation, with a supplement, appeared 1695: _The Life of Count Ulfeldt, Great Master of Denmark, and of the Countess Eleonora his Wife._ Done out of French. With a supplement. London. 1695. 8vo. Another novel by the same author, called _Casimir King of Poland_, is perhaps better known in this country, through a translation by F. Spence in vol. ii. of _Modern Novels_, 1692. [02] It is by a slip of memory that Mr. Birket Smith, in his first Danish edition of Leonora Christina's memoir of her life in prison, describes this work under the name of _De feminis eruditis_.