The representatives of the Spanish Jews thus distinguished themselves in science and poetry, while in France great impetus was given to the study of the Talmud. The Jews of the Italian peninsula, however, occupy a very low position in the history of culture at this period. Their poetic effusions, in harsh and barbaric language, whether liturgical or secular in character, lack the true charm of poetry, and their Talmud lore was obtained from foreign parts. Nathan ben Yechiel, of Rome, is the only Italian of that time whose name figures in Jewish literature. He compiled a Talmudic lexicon, under the title of "Aruch," in about 1001 or 1002; it was more complete than the earlier works of similar purpose, but was compiled, with little originality, from these older works, principally from the writings of Chananel, of Kairuan. This lexicon became the key to the Talmud. Kalonymos, of Rome, is also mentioned as a Talmudic authority. Rashi spoke of him with great respect; the community of Worms elected him as rabbi after the year 1096. However, he has left nothing in writing, and seems to have exerted no influence. The historical works of this period are silent respecting the political position of the Italian Jews, a proof that it was not unfavorable. Events of world-wide importance in western Europe, the extensive invasion by Christians of Mahometan Spain, and the first crusade against the Mahometans in the East, brought about important changes for the Jews of western Europe. The changes were chiefly of a deplorable kind, and interrupted their peaceful occupation with the Law. In the fortunes of Spain the Jews played no insignificant part, although their active interference is not conspicuously visible. They were helpful in digging the pit into which their great grandsons were to fall. The first powerful blow at the Islam dominion in the peninsula south of the Pyrenees was dealt by the Castilian king Alfonso VI, who was as brave in combat as he was clever in state affairs, and who placed more reliance on the sword and on diplomatic art, than on the cross and prayer. His purpose, to conquer the Mahometan kingdoms and principalities, was only attainable by fomenting dissensions among the rulers, stimulating rivalry between them, and playing off one against the other, thus weakening them all. To that end he required clever diplomatists, and among his subjects the Jews were the ones best prepared for the work. His knights were too clumsy, and his citizens too ignorant to be fitted for missions of a delicate nature. At the Mahometan courts of Toledo, Seville, Granada, there reigned a refined, cultured, intellectual tone, and frequent allusions were made in conversation to the brilliant history and literature of the Arabs. If an ambassador at these courts wanted to accomplish anything, he was obliged, not only to be acquainted with all the niceties of the Arabic language, but also to be familiar with its literature and the manners of the court.