When his own conduct during the time of their joint emperorship is compared with that of John it is seen that in love of country, in devotion to its interests, as well as in sagacity, he is greatly his superior. The difficulties that arose between them were in fact largely due to the jealousy, weakness, debauchery, and incompetence of John. When a youth he was simply a drunken reprobate. That a young emperor, who believed that he had been supplanted by another in his right to the sole occupancy of the throne, should resent references to his profligacy and his irregular life was natural enough, but Cantacuzenus cannot justly be blamed because he refused to surrender the government into his hands. Our estimate of the character of Cantacuzenus has to be based mainly on his own writings. But through them we know the man better perhaps than any other emperor. When dealing with events illustrating his own motives and conduct, he is an unconscious hypocrite. He gives us his version of all the principal events of his reign. His despatches and his speeches are reported at weary length, but they usually leave the impression of having been revised and modified by the light of his subsequent experience. His own narrative is confirmed to a considerable extent by that of Ducas, who, however, is open to suspicion as a partisan. His grandfather had belonged to the party of Cantacuzenus and had escaped into Asia Minor to avoid the vengeance of Apocaukus. Ducas describes Cantacuzenus as distinguished by the soundness of his judgment and by his great courage.[71] Cantacuzenus is great in accounting for his failures. Judged by his own narrative, which may be described as an _apologia pro vita sua_, he appears a respectable ecclesiastically minded man of mediocre talent, seriously desirous of the good of the people whom he governed, but anxious, above all, not only to become emperor but to found an imperial family. The vanity of Cantacuzenus leads him seldom to lose an occasion of reporting what friends or enemies say in his favour. When he sent the embassy to Pope Clement the Sixth to explain why he had employed Turks and to propose to render aid to the sovereigns of the West in the expedition which Clement contemplated, he remarks that the pontiff spoke in the highest terms of his moderation and kindness in not having treated his ungrateful enemies with more severity.[72] In his many negotiations with Rome he never fails to report expressions complimentary to his own sagacity, character, and conduct. In like manner he records the flattering expressions used regarding him by the Ottoman sultan, expressions which then, as now, are nearly destitute of all meaning, as if they were a serious representation of the sentiments of the writer. He cannot resist pointing out that Nicephorus Gregoras, whose History he declares to be false and malicious, had at one time awarded him unbounded praise.[73]