Who is Bertha Mason, and why is she locked away?

Bertha Mason is Rochester’s first wife, a Creole heiress from Jamaica whom he married for family advantage and then confined at Thornfield after what he describes as violent madness. The novel gives us his account — grievance, fear, and self-justification — more than hers. She appears as laughter in the corridor, a figure in Jane’s room, and finally as the woman whose existence voids the wedding.

Locking her away lets Rochester keep the appearance of an eligible widower-in-waiting while the legal marriage continues. That secrecy is the crime against Jane. Bertha is also the novel’s sharpest image of female confinement: a woman removed from view so a household can function. Reading her only as a monster repeats Rochester’s framing; reading her only as a symbol can erase the plot fact that she is a person the book barely lets speak. The character guide and the wedding chapters should be read together.