The history of the Swedish Revolution has never before been written in the English language. Even Gustavus Vasa is but little known outside his native land. Doubtless this is due in large measure to the difficulties which beset a study of the period. It is not a period to which the student of literature can turn with joy. One who would know Gustavus well must traverse a vast desert of dreary reading, and pore over many volumes of verbose despatches before he can find a drop of moisture to relieve the arid soil. Sweden in the early part of the sixteenth century was not fertile in literary men. Gustavus himself, judged by any rational standard, was an abominable writer. His despatches are in number almost endless and in length appalling. Page after page he runs on, seemingly with no other object than to use up time. Often a document covers four folios, which might easily have been compressed into a single sentence. Such was the habit of the age. A simple letter from a man to his wife consisted mainly of a mass of stereotyped expressions of respect. Language was used apparently to conceal vacuity of mind. Toward the close of the monarch's reign there was a marked improvement in literary style, and some few works of that period possess real worth. These have recently been printed, and as a rule have been edited with considerable care. The king's despatches are also being systematically printed by the authorities of the Royal Archives at Stockholm, and the cloud of ignorance which has hitherto hung over the head of Sweden's early monarch is lifting fast. The tenth volume of the king's despatches, known as _Gustaf I.'s registratur_ has now been published, carrying this contemporary transcript of the king's letters down to the summer of 1535. The only documents bearing on the Swedish Revolution and not yet published, are the MSS. known as _Gustaf I.'s rådslagar_, _Gustaf I.'s acta historica_, and _Gustaf I.'s bref med bilagor_,--all to be found in the Royal Archives at Stockholm,--and the MSS. known as the _Palmskiöld samlingar_ in the Upsala Library. All these I have carefully examined. I have also browsed during several months among the libraries of Sweden, and have spared no pains to get at everything, written or printed, contemporary or subsequent, that might throw light upon the subject. The most important of these materials are mentioned in the bibliography inserted immediately before the Index to this work. In order to add vividness as well as accuracy to the narrative, I have visited personally nearly all the battle-fields and other spots connected with this history. My descriptions of the leading contemporaries of Gustavus are based on a careful study of the portraits in the Gripsholm gallery, most of which were painted from life.