In the preceding part, wherein was made a comparative study of three important sources of _Tirant to Blanch_, we have had occasion to mention the real historical facts that form, in a more or less general way, the basis of Tirant’s career while in the service of the Emperor of Constantinople. Let us now transfer our researches to the field of history and try to determine what historical events underlie the hero’s various undertakings. Let us, moreover, examine all the features of _Tirant lo Blanch_ that give any indication of historical influence, in order that we may attain a better understanding of the author’s method in composing this work. The first question that confronts us is: What historical basis is to be found in the William of Warwick episode? The hero of the English romance of _Guy of Warwick_ is more or less a legendary personage. John Rous, a learned scholar and writer who lived between 1411 and 1491, in his writings concerning the legendary history of Warwickshire, names Guy as the second of the Saxon Earls of Warwick. We cannot cite any authentic historical facts about him. The story probably represents an old Saxon legend, perhaps in the form of a ballad, which in the course of time became a romance in French, and this was later translated into English. In the two fourteenth-century versions to which we have referred in Part III of this work, Aethelstan is represented as the King of England. This fixes the supposed time of Guy’s career as prior to 940, which marks the end of Aethelstan’s reign. The latter annexed Danish Northumbria, and, in 937, won the great battle of Brunanburh over the Danes, Scots, and Strathclyde Britons. This fact shows that there are at least some traces of authentic history in the romance, for in _Guy of Warwick_ we read of an invasion of the Danes. In _Tirant lo Blanch_, no dates are mentioned so that if we wish to establish the period in which the events described took place, we shall have to depend on the historical characters that are named, and the incidents, occurrences, and events that are narrated. The data that we may gather for this purpose probably will throw light on other matters in which we are interested.