Mahomet had continued from his boyhood to show his interest in studies, not only by his own reading but by welcoming other students, ‘for he was constantly striving to acquire those arts by which he should excel his predecessors and extend the bounds of his kingdom as far as possible.’ ‘He gathered to himself virtuous and learned men,’ says Phrantzes. He was, says Lonicerus,[528] an admirer of intellect and of the arts. He caused learned men and skilled artists to be brought to him at great expense. He employed Bellini,[529] a Venetian, and other artists, and loaded them with gifts. Virtue strove with vice within him. He had read all the history, says Critobulus, that was accessible to him in Arabic and Persian, and such Greek literature as had been translated into either of these languages, including Aristotle and the writings of the Stoics, and was skilled in astrology and in mathematics. A few years after he became sultan a certain George Ameroukes is found attached to his suite, a man described by Critobulus[530] as learned in philosophy, natural science, and mathematics. Mahomet made much of him, and called him often to discuss philosophical questions. Not a day passed without interviews with him or with other learned men attached to the court. In matters relating to foreign countries he was especially curious. Having met with the geographical writings of Ptolemy, he not only had them translated into Arabic, but charged George to make a map of the world with all the indications that he could give of the various countries, rivers, lakes, mountains, cities, and distances; for, says Critobulus, ‘the science of geography appeared to him necessary and most useful.’[531] In the course of his expedition to reduce Mitylene and Lemnos he visited the ruins of Troy and the traditional tombs of Achilles and Ajax and admired the good fortune of the heroes who had a poet like Homer to commemorate their deeds. ‘It is said,’ cautiously remarks his biographer, ‘that he believed that God had charged him to be the avenger of the ancient city.’[532] He frequently called the patriarch, the learned Gennadius, and discussed with him questions of theology. [Sidenote: Was Mahomet a religious fanatic?]