Born in Portsmouth, Fanny's mother has two sisters, one of whom has married Sir Thomas Bertram of Mansfield Park miles away and the other lives in a cottage on the grounds of Mansfield. This other sister, in an attempt to show off her own sense of self-importance and charity, offers to take one of her poor sister's children off her hands, and persuades Sir Thomas that Fanny could be her assistant in helping with the daily running of Mansfield and so should live there too.