One of the great mysteries of ancient Jewish history centers on the precipitous final editing and closure of the Talmud Yerushalmi at the end of the fourth century. The rabbinical batei midrash were closed down and halakhic discussions ceased without explanation. Various scholars have suggested that a general economic crisis in the Galilee of late antiquity was the basis for this development. Yet this explanation, while probable, is inadequate. This poster analyses both rabbinic texts and material archaeological findings to describe a deep division in the Jewish society of Eretz Yisrael in the late fourth century, the early Byzantine period. Specifically, we can trace the outlines of a bitter conflict between the Patriarch and his Sanhedrin based in Tiberias, and the large body of sages outside of Tiberias whether in Sepphoris, Caesarea, or Lydda. The Patriarchate both mobilized and controlled the financial resources of the Jewish community and had traditionally supported all of the rabbinical scholars whose discussions contributed to the text of the Talmud Yerushalmi. A breakdown of relations between Patriarchal circles and the sages outside Tiberias, on the basis of personal, cultural, and theological issues, led to the defunding of their institutions and their eventual closure. This in turn forced the Tiberian sages to wind down their halakhic creativity and close the Talmud Yerushalmi, hundreds of years before the closure of the Babylonian Talmud.