He and his wife Madame Therese Defarge are passionate advocates for revolution and regularly dispense and gather information from inside the wine shop.
When the story starts, Defarge is harboring Dr. Alexandre Manette, his old employer, who has just been released from eighteen years of unjust and secret imprisonment in the Bastille.
Defarge tells Manette’s story to a group of men in the hopes that they will spread the word of abuses perpetrated by the aristocracy - specifically, two brothers named St. Evrèmonde.
These papers prove nearly fatal to the novel's protagonist, Charles Darnay, in recounting a series of injustices and murders by his father and uncle.
Worse still, these infamies were committed against the family of Madame Defarge, Ernest's ruthless wife, who convinces him to denounce Darnay to the guillotine.