In 1215 Frederick II. became Emperor, and in 1231 he began to reorganize the kingdom of Sicily. Both in Sicily and in the course of his crusading expeditions in the East Frederick had been brought into close contact with the Muslims and was greatly attracted to them. He adopted oriental costume and many Arabic customs and manners, but, most important of all, he was a great admirer of the Arabic philosophers, whose works he was able to read in the original, as he was familiar with German, French, Italian, Latin, Greek, and Arabic. Contemporary historians represent him as a free-thinker, who regarded all religions as equally worthless, and attributed to him the statement that the world had suffered from three great imposters, Moses, Christ, and Muhammad. This opinion of Frederick is expressed in passionate words by Gregory IX. in the encyclical letter “ad omnes principes et prelatos terrae” (in Mansi. xxiii. 79), where he compares the Emperor to the blaspheming beast of Apocalypse xiii., but Frederick in reply likened the Pope to the beast described in Apoc. vi., “the great dragon which reduced the whole world,” and professed a perfectly orthodox attitude towards Moses, Christ, and Muhammad. It is quite probable, as Rènan (_Averroes_, p. 293) supposes, that the views ascribed to Frederick really are based on a professed sympathy towards the Arabic philosophers, who regarded all religions as equally tolerable for the uninstructed multitude, and commonly illustrated their remarks by citing the “three laws” which were best known to them. In 1224 Frederick founded a university at Naples, and made it an academy for the purpose of introducing Arabic science to the western world, and there various translations were made from Arabic into Latin and into Hebrew. By his encouragement Michael Scot visited Toledo about 1217 and translated Ibn Rushd’s commentaries on Aristotle’s _de coelo et de mundo_, as well as the first part of the _de anima_. It seems probable also that he was the translator of commentaries on the _Meteora_, _Parva Naturalia_, _de substantia orbis_, _Physics_, and _de generatione et de corruptione_. Ibn Sina’s commentaries were in general circulation before this, so that they were very probably the “commentaries” referred to in the Paris decree of 1209, but we do not know who was responsible for their rendering into Latin, save that they almost certainly proceeded from the college at Toledo. The introduction of Ibn Rushd, not of great repute amongst the Muslims, bears evidence to the weight of Jewish influence in Sicily and in the new academy at Naples. We know that Michael Scot was assisted by a Jew named Andrew.