No matter how many times I visited the great medievalist Israel M. Ta-Shma in his Jerusalem home, I couldn't help noticing the books first. They were everywhere, filling and overflowing the separate apartment that served as his workspace. Passing the silent, darkened bookshelves, I would make my way to the brightly lit study where he sat in the company of piles of manuscripts, still more books, and a computer.

It never took long for our conversation to turn to scholarly pursuits, usually sparked by the specific question that had brought me there. Responding, Ta-Shma would launch into a discourse in which he generously shared his magisterial command of his main field of research, medieval rabbinic literature, and especially its treasury of still-unpublished manuscripts. There wasn't much opportunity for me to do more than inject an observation here and there, but it was sheer pleasure to sit and drink it all in.

Throughout his scholarly career, Ta-Shma was occupied with, and preoccupied by, certain guiding issues and themes. But he was also incredibly restless, perpetually on the lookout for new vistas to explore and new angles from which to examine well-rehearsed questions. "I love new things," he would exclaim to me:  discovering new manuscripts, identifying the authors of hitherto unattributed works, enlisting out-of-the-way scholarship to shed new light on rabbinic literature. He especially reveled in restoring luster to neglected centers of Jewish learning, casting his net over places like medieval Poland, Russia, and Syria where few if any scholars had gone before.

Like a magnet, though, he was always drawn back to Italy, Greece, and Byzantium, and to what he saw as the central role played by the Jews of these regions in the development of medieval and especially Ashkenazi Judaism. It was known that the forebears of Franco-German Jewry had hailed from southern Italy, a region ruled by Greek-speaking Byzantium in the period when Jews were moving north. The name of a leading Ashkenazi family, Qalonymos, is a hint, being the Greek rendering of Shem Tov, or "Good Name." But where did the traditions of southern Italian Jews themselves originate?

Ta Shma argued that fundamental differences between Ashkenaz and Sefarad could largely be traced to the land of Israel. Much of the latter's heritage was conveyed to Italy by scholars who reached there by sea. But, like southern Italy, Eretz Yisrael was also ruled by the Byzantine Empire for most of the early Middle Ages. And so it was to Greece and Constantinople that he proceeded to direct his gaze, uncovering there a vibrant center of Jewish life and rabbinic creativity. Many of the riches produced by that community, in the form of commentaries on Talmud and Midrash, were, he contended, passed westward to Italy and thence to Germany.

Ta-Shma found proof of this chain of transmission in the life's work of R. Isaiah of Trani (1200–c. 1260), reconstructed by him through a painstaking review of hitherto unappreciated manuscript evidence. Providing a critical link between Byzantium and Ashkenaz, Rabbi Isaiah simultaneously brought eastern traditions to Ashkenaz and the achievements of the Franco-German school of Tosafists-- the grandchildren of Rashi and their disciples—to Byzantium. No wonder, observed Ta-Shma, that Rashi's grandson, the great French sage Jacob Tam (c. 1100–1171), would declare of southern Italy's cities that "Out of Bari shall go forth the Law, and the Word of God from Otranto."

Ta-Shma admitted that his explorations of the Byzantine connection only scratched the surface, and that much more lay waiting beneath. Bringing it to light was a task he left to others, whom he urged to follow his example in the restless search for "new things." 

Jeffrey R. Woolf is a senior lecturer in the department of Talmud at Bar-Ilan University.