A Franciscan friar from Hibernia, William is a former inquisitor who relies on empiricism and reason to understand the world. He possesses a striking physical presence, standing exceptionally tall with a beaky nose and penetrating eyes. He utilizes new technologies like eyeglasses and approaches the abbey's mystery with sharp deductive logic rather than brutal certainty.

Adso is a young Benedictine novice serving as scribe and disciple to William. He is eager to learn and deeply respects his master, though he frequently struggles to understand the complex political and theological disputes surrounding him. His youth makes him susceptible to both confusion and worldly temptations.

The abbot of the Benedictine monastery takes immense pride in his institution's wealth and its famous library. He previously built his reputation by carrying the body of Thomas Aquinas. While he desires to solve the mysterious death of a monk, he prioritizes the honor and secrecy of the abbey above all else.

A tall and pale monk, Malachi serves as the melancholy head librarian. He strictly controls access to the books, ensuring only approved texts are distributed. He carefully guards the secrets of the labyrinth and maintains strict discipline in the scriptorium.

An elderly and blind monk who has lived at the abbey for decades. He exerts immense ideological influence over the scriptorium, vehemently opposing any form of comedy or artistic representation that induces laughter. He believes such merriment subverts reason and leads directly to sin.

A notorious Dominican inquisitor sent to enforce the Pope's will. He uses fear and strict adherence to doctrine to extract confessions. He acts as a direct foil to William, preferring brutal certainty over reasoned investigation.

The cellarer manages the monastery's supply of food and wine. He is a stout, physically strong man with a vulgar appearance. He harbors a complex past involving heretical movements and maintains questionable habits within the abbey walls.

A vagrant-like monk born to serfs, Salvatore speaks a bizarre amalgamation of Latin, Italian, and French. His face is marked by eczema and a dog-like mouth. He assists the cellarer and willingly procures illicit items and people from the local village.

Before the story begins, Adelmo was a highly skilled and renowned manuscript illuminator. His fantastical, sometimes monstrous drawings drew both admiration and harsh criticism from his peers. His unexplained death sets the entire investigation in motion.

An elderly Franciscan friar in exile, Ubertino holds a fierce belief in the absolute poverty of Christ. His impassioned preaching makes him a target for the Pope's wrath, forcing him to seek sanctuary with the Benedictines. He values spiritual purity over intellectual reason.

The abbey's herbalist manages the balneary, the infirmary, and the medicinal gardens. He shares William's scientific curiosity and firmly believes nature can be studied like a book. He possesses deep knowledge of both healing plants and dangerous toxins.

The assistant librarian leverages his access to restricted knowledge to extract sexual favors from younger monks. He lusts heavily after Adelmo and behaves erratically following the young illuminator's death.

A dedicated scholar and translator of Greek and Arabic texts, Venantius holds a deep devotion to Aristotle. He possesses a strong curiosity that drives him to seek out hidden knowledge within the abbey's restricted areas.

A young Scandinavian monk studying rhetoric. Benno deeply resents the intellectual restrictions placed upon the monks and constantly seeks to uncover the library's hidden secrets. He is highly observant of his peers' illicit activities.

The master glazier of the abbey. He takes great pride in his craft and the abbey's physical treasures. He is deeply curious about new technologies but fears they might represent forbidden magic.

A gossipy and resentful monk who copies manuscripts on loan. He wears a perpetual sneer and openly criticizes the fact that non-Italian monks control the abbey's most prestigious positions.

At nearly one hundred years old, Alinardo is the eldest monk in the abbey. He harbors a deep-seated anger over being passed over for the position of head librarian decades earlier. His speech is erratic and frequently touches on religious visions.

The Minister General of the Franciscan order. A historical figure, Michael balances the strict religious duties of his order with the tense political realities of negotiating with the powerful Papal court.

A bishop within the Franciscan delegation. He assists Michael of Cesena in presenting a unified front against the Inquisition's representatives.

A determined adversary of the Pope who travels with the Minorites to lend weight to their theological arguments.

A powerful Cardinal who represents the interests of Pope John XXII. He seeks to maintain ecclesiastical dominance over the rebellious Franciscan factions.

A young woman from the local village who trades her body for food and supplies from the abbey. She is beautiful, impoverished, and highly vulnerable to the harsh judgments of the church authorities.

An illuminator working in the scriptorium. He aligns himself with the Italian faction that deeply resents foreign leadership in the library.

Another illuminator in the scriptorium who shares the Italian faction's prejudice against the current library administration.

An illuminator who labors silently under the strict rules of the head librarian.

An illuminator contributing to the vast output of the monastery's copying efforts.

An illuminator who aligns with the faction complaining about the abbey's internal politics.