Work He became known for his Iggeret, according to Ginsberg the earliest extant halakhic work surviving from the Geonic period, an epistle to the Jews of Kairouan in Tunisia. This epistle, the first known example of its kind for advocating the dissemination of the Babylonian Talmud, dated to around 800/810 came to light from its discovery among the Geniza records. It contains a polemical attack on what he regarded as the ignorant customs prevailing among Palestinian Jews of Eretz Israel (minhagei eretz yisrael) at that time, beliefs and practices which had, he argued, spread to major centres of Talmudic learning in North Africa, such as Kairouan, from which they radiated out in turn further west to Spain. This iggeret, a virulent broadside against the Land of Israel/Palestine, which was held in high reverence in Jewish communities, and the whole Palestinian rabbinical tradition, might have struck its readership as scandalous. Though widely distributed, did not appear to have much effect on the community it addressed, since Palestinian influences remained strong there centuries later, as one can see from Sherira Gaon 's Iggeret to Kairouan and in the work of his son Hai Gaon. However the arguments made are echoed in broader diatribes and defenses of piyyut in much later times. The claim to a superior authority in religious matters was buttressed by the claim that the Babylonian academies, namely the Torah sages according to the Seder Olam Rabbah, departed, with Jeconiah, to Babylon 12 years prior to the Siege and destruction of Jerusalem in 586, and only after their safety was secured was permission granted to destroy Jerusalem and its Temple. The exile itself was, he argued, an 'act of charity (tzedakah)' by God. The Babylonian yeshivot conserved the strength (gevurah) of the Jewish contingent of troops (gibborim) who had formed part of the earlier evacuation, so that the Babylonian scholars, heirs to this exile of the strong, were themselves warriors (gibborei) of Torah. In terms of his rhetoric of persuasion, Pirqoi ben Baboi's mode of thought evinces three simple assumptions: What distinguishes Babylonian Judaism from its Palestinian counterpart is that the former never experienced persecution (shemad), whereas it was continuous with the latter. The persecutions in Palestine broke the transmission of the Oral Torah there. Therefore, the authentic Judaic tradition is conserved in Babylon. That in Palestine is unreliable. His driving aspiration was to impose the halakhic hegemony of the