Mary is a kind, pious woman living in London with her son, Barnaby. She supports herself using a modest annuity provided by Geoffrey Haredale. She bears a heavy emotional burden from her past, fiercely protecting her son while harboring dark secrets regarding her deceased husband.

Barnaby is a 23-year-old man living in London with his mother. He has an unspecified intellectual disability that causes others to underestimate him or treat him as a child, though he possesses a unique, untraditional wisdom. Known for his eccentric dress and the raven he carries on his shoulder, he is energetic, boisterous, and deeply devoted to his mother.

Gabriel is an honest, highly respected locksmith who lives in Clerkenwell. He is a frequent patron of the Maypole Inn in Chigwell, much to his wife's dismay. He frequently acts as a steady, virtuous presence, attempting to help his friends and navigate the volatile temperaments within his own household.

Dolly is Gabriel and Martha's beautiful daughter. She acts as a go-between for the forbidden romance of her friend Emma Haredale. Described as a coquette and a somewhat spoiled child, she struggles with her own emotional immaturity, particularly regarding her feelings for Joe Willet.

Joe is the 20-year-old son of the Maypole's landlord. Despite being an adult capable of heroic actions, he is constantly mistreated and infantilized by his father and the inn's patrons. He is deeply in love with Dolly Varden, though her coldness and his father's bullying drive him to consider running away to join the army.

Hugh is the hostler at the Maypole Inn. Described as living like an animal, he has had a rough life following the execution of his mother. He is highly susceptible to alcohol, which he uses to numb his pain, and possesses a wild, violent nature that makes him easily manipulated by those with wealth and power.

John Chester is Edward's wealthy, conniving father. Obsessed with his own image and maintaining a luxurious lifestyle, he uses charm and polite manners to mask his ruthless nature. He actively works to destroy his son's romance with Emma Haredale because he needs Edward to marry an heiress to settle his hidden debts.

Geoffrey is the owner of the Warren estate in Chigwell. He is the brother of the murdered Rueben Haredale and guardian to his niece, Emma. He is a devout Catholic who is brutish and headstrong but deeply protective of his family. He maintains a fierce, mutual enmity with his old schoolfellow, John Chester.

Edward is John Chester's son. He has grown up in luxury but feels useless and yearns to make a name for himself. He is deeply in love with Emma Haredale, a relationship complicated by their fathers' bitter rivalry and his own father's demands that he marry for money.

Lord George is a nobleman and the leader of the Protestant Association of England. He passionately campaigns against recent laws that reduce discrimination against Catholics. While he genuinely believes in his cause, he is ambitious, somewhat naive, and easily manipulated by his treacherous secretary.

Gashford is Lord George Gordon's malicious, treacherous secretary. He uses his position to stoke religious fanaticism and further his own sinister agendas. A former Catholic and old schoolfellow of both Haredale and Chester, he secretly plots violence and destruction while outwardly praising his master.

Ned Dennis is the hangman of Tyburn gallows. He takes intense pride in his grim profession and fears that granting Catholics more political power will threaten his livelihood. He is recruited into the Protestant Association and uses the movement as an excuse to unleash his violent impulses.

Martha is Gabriel's temperamental wife. She is characterized by her constant complaining and sudden theatrics. She often uses religion as a weapon, turning to a Protestant manual primarily when she wishes to express ill-temper or assert her superiority over her husband.

Simon is Gabriel Varden's vain, conceited apprentice. He hates his employer and is obsessed with his own physical appearance, particularly his shapely legs. Secretly, he acts as the captain of the 'Prentice Knights, a clandestine group of apprentices plotting to gain power over their masters.

Miss Miggs is the maid and confidante in the Varden household. She is combative, false, and frequently encourages Martha Varden's worst tendencies against Gabriel. Despite claiming to despise all men, she is aggressively infatuated with Simon Tappertit.

Old John is the landlord of the Maypole Inn in Chigwell. He is immensely sure of his own intelligence and eloquence, surrounded by a group of cronies who validate his opinions. He is emotionally abusive toward his adult son, treating him as an impetuous child and demanding his silence.

Emma is Geoffrey Haredale's niece. She carries the childhood trauma of her father Rueben's unsolved murder. Despite her guardian's strictness and the feud between their families, she maintains a secret correspondence with Edward Chester, facilitated by her friends.

John Grueby is Lord George Gordon's honest servant. Unlike Gashford, he sees the danger in stoking religious fervor and frequently worries that his master is inciting more violence than he can control. He provides a voice of reason within the Protestant Association.

Grip is Barnaby's intelligent pet raven. He is hypervigilant, often observing details that the human characters miss. He constantly repeats phrases like "never say die" and "I'm a devil," which often hold symbolic truth regarding the situations Barnaby finds himself in.

Barnaby Rudge Sr. is the former steward to the late Rueben Haredale. He has been presumed dead for 22 years following the murder of his employer. His violent legacy casts a long shadow over his wife Mary and his son Barnaby Jr., shaping their lives and driving them into poverty.

Solomon is the parish clerk of Chigwell and one of Old John Willet's loyal cronies. He is known for ritually retelling the story of Rueben Haredale's murder every year on its anniversary, helping to keep the past alive in the village's memory.

Stagg is a blind man living in London who hosts the clandestine meetings of the 'Prentice Knights. He is highly perceptive despite his blindness and frequently mocks his patrons behind their backs, operating on the fringes of the city's criminal underbelly.