In 1489, a magnificent illustrated Passover Haggadah was sent as a bequest to the Monastery of Saint Quirinus at Tegernsee in southern Germany. Shortly afterwards, the monastery’s librarian sent the book to a Dominican friar named Erhard von Pappenheim, a Hebraist and expert on Jewish practice, and asked him to write a prologue. In response, Erhard wrote a remarkable treatise that is arguably the earliest quasi-ethnographic account of Jewish practice in early modern Europe and an extraordinary window onto a fifteenth-century Christian’s perception of Jews and Judaism. The Monk’s Haggadah brings together a facsimile edition of the codex in color, a critical edition of the Latin text of Erhard’s prologue, an English translation of the Latin text, and a translation of the Hebrew text of the Haggadah. Additionally, the volume’s editors provide historical context, explore the codicology, illustration, and patronage of the volume, and describe its Christian theological background. An absolutely unique document, this Haggadah stands to change many long-held conceptions about Jewish-Christian relations in the late Middle Ages and early modernity.