Medardus is a monk and the main character in the story. He is in charge of the artifacts in the Capuchin convent. One interesting relic is the devil's elixir, which Medardus drinks out of necessity and discovers the truth about his family and himself.

Count Victorin is Medardus's stepbrother and a notorious womanizer. He has an affair with a baron's wife and is also interested in Aurelia, Medardus's love interest.

Aurelia is Medardus's love interest and the daughter of Baron von F___. She first meets Medardus during a confession, where she tells him that she loves him.

Francesco is Medardus's and Victorin's father. He is also a painter who used to be part of the Lime Tree convent, where Medardus was born.

Other notable characters include Hermogen, Baron von F___, Euphemia, Pietro Belcampo, Leonardus, Reinhold, Prince von Rosenthurm, The Duke of Neuenburg, and Father Spiridion.