At the same time that the Karaite schism occurred, the Chazars, a Tartar tribe, were converted to Judaism. Reports of the existence of a Jewish kingdom had reached the Jews of Western Europe. Hasdai ibn Shaprut wrote a letter of inquiry on this. He received a reply from the King of the Chazars, and these two letters are the chief source of information concerning this remarkable event. Toward the end of the tenth century the kingdom of the Chazars was conquered by the Russians. Judah Halevi, who wrote his Kuzari about 1140, used the story of the conversion of the Chazar King in the form of a philosophic dialogue between him and the rabbi who converted him. The knowledge he had of an independent Jewish state was the basis of the fanciful reports circulated by an adventurer who called himself Eldad Hadani and pretended to be a descendant of one of the lost ten tribes. Their habitation and modes of life he described in a book. He appeared in the tenth century in Morocco, but nothing is known as to what finally became of him. In the ninth century, the literature of religious hymns, Piyut, begins. The authors of these are called Payetanim (poets). Their works are characterized by arbitrary handling of the Hebrew grammar, by the creation of new words in an arbitrary style, and finally, by obscure allusions to the Midrash. The oldest of these poets are Jose ben Jose and Jannai. Their successor, Eleazar ben Kallir, is the most prolific of all. Of his life we know nothing with certainty. The literary activity of the Jews of Europe began in the ninth century. The first work is probably the Josippon, a history of the Jews from the destruction of Babylon by Cyrus to the downfall of Jerusalem in 70, which was ascribed to Josephus Flavius. Another anonymous writer, who lived in Italy in the ninth century, is the author of the Midrash, called Pirke Rabbi Eliezer. But the first Jewish author who lived in Europe, known by name, is Sabbatai Donolo (913-982), who wrote on medicine, astrology, and Kabbala. CHAPTER V THE JEWS OF EUROPE (1040-1215)