  Giles of Rome exerted considerable influence also in other fields of ethics, such as the theory of virtues. The most developed expression of his position is not to be found in a Commentary on Aristotle, but rather in his De regimine principum, the most successful “mirror of princes” of medieval political thought, which is still conserved in more than 300 manuscripts in its original Latin version, to which many translations in European vernaculars must be added. Written most probably between 1277 and 1280 the De regimine is acknowledged to be one of the most successful attempts at mediating Aristotle’s practical philosophy, and in particular his “ethical and political language” to the Latin West. Giles was the first to structure a mirror of princes in three books along the lines of a scheme — ethica-oeconomica-politica — which played an important role in the reception of Aristotle’s moral and political philosophy in the Middle Ages (Lambertini 1988). The author takes great care to give the impression that he is mainly relying on Aristotle’s text, providing numerous quotations from the Nichomachean Ethics, from the Politics and from the Rethoric. Scholars should not overlook, however, that his reception of Aristotle is not as direct as it can seem and that Giles is deeply influenced by a tradition in the interpretation of Aristotle’s practical philosophy. In this tradition Aquinas plays a very important role for Giles, so that, while Aristotle is the authority who is quoted on almost every occasion, it is the unnamed Aquinas who, with his Sententia libri Politicorum, De regno, Summa Theologiae, exerts a really decisive influence on De regimine. While discussing particular topics, Giles skillfully adapts Aristotle to his own purposes. This emerges with clarity in the first book, devoted to ethics, where Giles’ classification of virtues is heavily dependent on the Summa Theologiae and, therefore, on Aquinas’ reinterpretation of the Aristotelian heritage. For example, Giles here defines prudentia as a virtus media, sharing the nature of moral as well as of intellectual ones, a doctrine which can by no means be traced back to the Stagirite (Lambertini 1991, 1992, 1995, 2000). In the second book Giles deals with the ethics of man as head of the family, covering many topics, from children rearing and education to the rule over servants. To this purpose, he exploits a wide range of sources, and also medicine authors (Lambertini 1988, Martorelli Vico 2008). As Giles wrote his De regimine, the pseudo-Aristotelian Oeconomica were not yet available in traslation to the Latin West; still, he managed to discuss also economic topics, as far as they are relevant for the household of a royal family or for a high-class household in general. Here he condemns usury, criticizes other economic practices as not suitable for a prince, and insists on the primary role agricolture should play (Lambertini 2015) 