While Palestinian Judaism suffers under Roman persecution and the aftermath of two devastating revolts, the Babylonian Jewish community — established since the Exile of 597–586 BC — expands in size, prosperity, and scholarly authority. Under the Parthian and later Sassanid Persian empires, Babylonian Jews enjoy significant autonomy under the Exilarch (Resh Galuta), who traces his lineage to the Davidic royal house. The academies of Sura (founded by Rav, ~219 AD) and Pumbedita become the twin centers of Jewish scholarship, eventually producing the Babylonian Talmud (~500 AD) which supersedes the Jerusalem Talmud as the normative text of worldwide Judaism.