Klaus-Dieter Weigel had been sorting his late aunt Margarete's belongings for three weeks when he opened the cedar trunk in the upstairs back bedroom.

He was 71, a retired professor of systematic theology at the University of Tübingen, and not easily surprised by old books. The bound codex at the bottom of the trunk surprised him.

It was small, roughly 17 by 12 centimeters, in a worn calfskin binding, and the first page bore the unmistakable hand of a 12th-century Rhineland scribe.

Weigel read German, Latin, and Middle High German fluently. By the third folio he had set the book down and gone outside to stand in the garden for ten minutes.

The codex contains fourteen letters in the voice of Hildegard of Bingen, the visionary abbess, composer, and natural philosopher who died in 1179. Twelve of the letters appear to be previously unknown.

Two correspond to outgoing letters mentioned in Hildegard's known correspondence but whose contents were lost.

Two correspond to outgoing letters mentioned in Hildegard's known correspondence but whose contents were lost.

Weigel brought the codex to the Stadtbibliothek Trier, where paleographer Ursula Brandt confirmed, after a week of comparative analysis, that the hand matches that of Volmar of Disibodenberg, Hildegard's longtime secretary and editor.

The letters span roughly the period 1167 to 1175. They address a Cistercian abbot in Lorraine, a noblewoman in Bavaria, two clergy in Cologne, and, most striking, a Jewish physician in Mainz named Eliezer ben Yitzhak.

The letter to ben Yitzhak discusses the medicinal use of fennel and rue and includes a careful, almost collegial request for his opinion on a recipe involving betony.

No previously known Hildegard text addresses a Jewish correspondent directly, and the tone, neither polemical nor condescending, surprised the committee that first reviewed it.

How the codex reached Margarete Weigel is not entirely clear. Family records suggest her grandfather, a parish priest in the Eifel region, acquired a small library at auction in 1893 from the estate of a defrocked Benedictine.

The book was likely catalogued, vaguely, as "devotional, Latin, twelfth century," and shelved without further inspection.

It then traveled with the family through two world wars, a flight from Silesia in 1945, and three subsequent moves, before settling in the attic of a row house in Trier.

The codex is now on loan to the library while a full digital facsimile and critical edition are prepared, a project Brandt estimates will take roughly three years.

Weigel has declined offers from private collectors and intends to donate the manuscript to the Eberhard Karls University library in Tübingen once the edition is complete.

He told an interviewer that he sometimes wonders whether his aunt knew what she had. She had been a quiet woman, fond of birds, who never spoke of the trunk.

Some discoveries arrive with expeditions and grant funding. Some arrive in a cedar trunk that has been waiting, patiently, in someone's attic for 132 years.