In her postcolonial masterpiece Wide Sargasso Sea, Jean Rhys declared that ‘There is always the other side, always’. Published in 1966, Wide Sargasso Sea wrote back to Charlotte Brontë’s Jane Eyre by rewriting the character of Bertha Mason. As the mad Creole antagonist trapped in Rochester’s attic, Brontë’s depiction of Bertha was filled with descriptions of savagery and bestial lunacy. Bertha was pushed to the margins of Jane Eyre, completely voiceless within the narrative of her racialised, sexualised madness. Born in Dominica in 1890, Rhys felt a deep sympathy for Brontë’s madwoman from her first reading of Jane Eyre as a child. Her life as a Creole outsider in England strengthened this connection, as Rhys became more and more like Bertha through her own experiences as a similarly isolated, racialised woman, whilst writing Quartet (1928), Voyage in the Dark (1934), and Good Morning, Midnight (1939). In this thesis I argue that Rhys drew from her experiences of marginalisation, precarity and prejudice to illustrate a possible ‘other side’ of the colonial and patriarchal attitudes that formed Brontë’s madwoman, and that she did so long before the 1960s. Previously, Rhys’s writing back to Brontë has been examined solely within the connections between Wide Sargasso Sea and Jane Eyre. Because of this limited scope of analysis, it is widely thought by academics and Rhys’s biographers that Brontë’s influence upon Rhys began and ended with Wide Sargasso Sea. However, this resistive act of writing back in fact began far sooner than previously recognised. My thesis argues that Rhys began her postcolonial and feminist criticism of Brontë and Brontë’s representation of the West Indies, in her earliest modernist works. Analysing a selection of Rhys’s fiction, this thesis reads the Rhysian woman as a modern manifestation of Bertha. Tracing Rhys’s postcolonial inversion of Brontë’s Eurocentric gothic, this thesis also examines the gothic modes and motifs within Rhys’s modernist fiction. The echo of two of Brontë’s other marginalised women, Céline Varens and Ginevra Fanshawe of Jane Eyre and Villette, are also read within Rhys’s female characters. Like Bertha, these minor protagonists closely resembled Rhys’s experiences as a mistress and demi-mondaine, and she was able to rewrite Brontë’s contemptuous representation of Céline and Ginevra with the same lens of sympathy that she applied to the Creole lunatic. With attention to both textual evidence and the author’s contextual experiences, this thesis traces how Rhys was continually motivated and influenced by Brontë’s representations to write back from the ‘other side, always’.