One who has long been engaged in historical study and teaching, if he undertakes to prepare such a work as the present, has occasion to traverse certain periods where previous investigations have made him feel more or less at home. Elsewhere at least his course must be to collate authorities, follow such as he deems best entitled to credit, and, on points of uncertainty, satisfy himself by recurrence to the original sources of evidence. Among the numerous works from which I have derived assistance, the largest debt is due, especially in the ancient and mediæval periods, to Weber's _Lehrbuch der Weltgeschichte_, which (in its nineteenth edition, 1883) contains 2328 large octavo pages of well-digested matter. Duruy's _Histoire du Moyen Age_ (eleventh edition, 1882), and also his _Histoire des Temps Modernes_ (ninth edition), have yielded to me important aid. From the writings of Mr. E. A. Freeman I have constantly derived instruction. In particular, I have made use of his _General Sketch of European History_ (which is published in this country, under the title, _Outlines of History_), and of his lucid, compact, and thorough _History of European Geography_. The other writings, however, of this able and learned historian, have been very helpful. Mr. Tillinghast's edition of Ploetz's _Epitome_ I have found to be a highly valuable storehouse of historical facts, and have frequently consulted it with advantage. The superior accuracy of George's _Genealogical Tables_ is the reason why I have freely availed myself of the aid afforded by them. Professor (now President) C. K. Adams's excellent _Manual of Historical Literature_, to which reference is repeatedly made in the following pages, has been of service in preparing the lists of works to be read or consulted. Those lists, it hardly need be said, aim at nothing like a complete bibliography. No doubt to each of them other valuable works might easily be added. As a rule, no mention is made of more technical or abstruse writings, collections of documents, and so forth. The titles of but few historical novels are given. Useful as the best of these are, works of this class are often inaccurate and misleading; so that a living master in historical authorship has said even of Walter Scott, who is so strong when he stands on Scottish soil, that in his Ivanhoe "there is a mistake in every line." With regard, however, to historical fiction, including poems, as well as novels and tales, the student will find in Mr. Justin Winsor's very learned and elaborate monograph (forming a distinct section of the catalogue of the Boston Public Library), the most full information up to the date of its publication. Most of the historical maps, to illustrate the text of the present work, have been engraved from drawings after Spruner, Putzger, Freeman, etc. Of the ancient maps, several have been adopted (in a revised form) from a General Atlas. That the maps contain more