Heart of Darkness (1899) is a novella by Polish-English novelist Joseph Conrad about a narrated voyage up the Congo River into the Congo Free State in the so-called heart of Africa.
(from wikipedia.org)

Joseph Conrad (1857 - 1924) was a Polish-British writer regarded as one of the greatest novelists to write in the English language.
Though he did not speak English fluently until his twenties, he was a master prose stylist who brought a non-English sensibility into English literature. (from wikipedia.org)