Castle Richmond is set in southwestern Ireland at beginning of the Irish famine. Castle Richmond is situated on the banks of the Blackwater River in County Cork. Trollope's work in Ireland from 1841 to 1859 had given him an extensive knowledge of the island, and Richard Mullen has written that all the principal strands of his life were formed in Ireland. The complicated plot features the competition of two Protestant cousins of English origin, Owen Fitzgerald and Herbert Fitzgerald, for the hand of Clara Desmond, the noble but impoverished daughter of the widowed Countess of Desmond, providing the novel's principal dramatic interest.