Historians are rarely satisfied with their evidence: They want more. When writing my political life of Abraham Lincoln, I lamented that the Civil War president didn’t keep a private journal. Now, as the head of one of Oxford University’s historic colleges, I have another fancy: to identify the anonymous 12th-century Jewish traveler whose Hebrew prayer book, quite possibly the oldest extant in Europe, is one of the many treasures in my college’s library. Although this particular jewel has been in our possession for centuries, it has only now become the subject of scholarly scrutiny and excitement.

The outer leaves of the Ashkenazic prayer book, originally blank, contain a list in a Sephardic script of the names of the debtors to whom the owner had lent money on his travels—written in Arabic but in Hebrew letters. Corpus Christi College, Oxford

Corpus Christi College, which will reach its 500th birthday in 2017, is celebrated as Oxford’s first Renaissance institution. The bishop-statesman Richard Fox, right-hand man to the Tudor monarchs Henry VII and Henry VIII, founded the college to instruct students in the sciences and the languages of the Bible: Hebrew and Greek. From the first, Corpus took a lead in Jewish learning and built an acclaimed library. Among the scores of manuscripts the college used for teaching its young men were Hebrew texts, several donated by the first president and noted collector, John Claymond. How and when he acquired them we don’t know—and this is only a part of their mystery. They are the jewels of a small but spectacular collection of medieval Anglo-Jewish books.

These materials shaped the scholarship that gave Corpus a primary role in the translation of the King James Bible. The 400th anniversary of that publication, in 2011, sparked particular interest in the Hebrew manuscripts at Corpus. These include commentaries by the acclaimed medieval French rabbi, Rashi; other items present passages from the Hebrew Bible with a literal translation in Latin written, from the outset, directly above the Hebrew text. They point to the cooperation between Jewish and Christian scholars, eager to help non-Jews learn Hebrew and understand the primary sources of a shared scriptural tradition. The texts could equally have been used to teach Jews Latin—not impossible, given that most English law, property transactions and accounting were conducted in Latin. Command of the language would have been especially beneficial to Jewish financiers in doing business.

Most striking of all these holdings is a unique Hebrew prayer book, or siddur. It was designed for those who followed the French-German rite; its appendix sets out the kosher rules on the slaughtering of animals. The manuscript’s 400 pages are written in an Ashkenazic hand. But there is a surprising personal feature, too. The outer leaves of the book, originally blank, contain a list in a Sephardic script of the names of the debtors to whom the owner had lent money on his travels. Remarkably, they are written in Judeo-Arabic: that is, in Arabic but in Hebrew letters. They reveal that the prayer book, which originated in central Europe, had come into the possession of a Sephardi Jew from the south of Spain, then a Muslim country. The owner settled in England and used some of its pages to record business transactions. The document is the only one of its kind: We know of no other texts written in this language in England during the Middle Ages.

This siddur probably dates from the 12th century, with some experts deeming it the oldest surviving Jewish prayer book of European origin. Remarkable though this might be, its particular age matters rather less to historians than what the document so graphically exemplifies through its compelling human story: the wanderings and fluctuating fortunes of the Jews during the Middle Ages. There are hints that the prayer book was for a time in the hands of the powerful Kalonymus family, who moved from Italy to Germany in the ninth century. What is beyond doubt is that, as one scholar explains, the work’s liturgical origins lay in Germany and its sometime possessor was “a Jew from Spain, writing in his native tongue Arabic, who had come to live in England, and lent money to a number of Christian dignitaries there.”

Who was this itinerant? Why did he leave Spain? With the closing of what some have called a Golden Age for Iberian Jews, was he a victim of that intolerance? Why did he opt for England as his new home? How was he treated there? How had he made the money that gave him the means to lend? Without further evidence, the answers to these inquiries remain lost in time. But the hidden human story is tantalizing.

One thing is beyond question. Our Sephardi Jew was part of a transnational network of Jewry, whose breadth of outlook was reinforced by the interaction of Christian/Gentile and Jewish culture. He is likely to have made his home in the Jewish Quarter of Oxford, close to the site of some of the early colleges of the university. Although the Jews were grievously driven out of England by King Edward I’s Edict of Expulsion in 1290, not to be readmitted until the rule of Oliver Cromwell, over 350 years later, their cultural influence persisted during that time.

Corpus Christi College wasn’t established until 1517, built on land adjacent to the earlier Jewish Quarter. But the college’s Renaissance foundations, as its library’s manuscripts and early printed books reveal, depended on the continuing influence of Hebraic scholarship and even of Jews themselves during the period of their expulsion. The story of Renaissance Corpus, as of other institutions of that era, is a story of political boundaries made porous by international scholarship.

The scholar who is now cataloging the Ashkenazic prayer book and the other Hebrew manuscripts at Corpus has praised their “breathtaking quality and interest,” judging them “the most important collection of Anglo-Jewish manuscripts in the world.”

For reasons of conservation and security, the prayer book is not routinely on display, but is available to view by appointment. To mark Corpus’s 500th anniversary, however, the College has developed plans for a Special Collections Center, work on which—funding permitting—will start as part of the Quincentenary celebrations. In this Center visitors will be able to view and work with these extraordinary materials and our other Renaissance treasures. By improving access for scholars and the public, we want these texts to act as a continuing reminder of the historic durability and vibrancy of Jewish culture in the face of intolerance and anti-Semitism. With racial and religious prejudices resurfacing so powerfully today in parts of Europe and the world beyond, no project could be more timely. And—a happy thought besides—the swelling of scholarly attention might help us establish the identity and experience of our mysterious Sephardi Jew.