Who wrote the novel Things Fall Apart?

Chinua Achebe, in 1958, and it was written in direct answer to something. He had read Joyce Cary's Mister Johnson at university - a novel about Nigeria by an Englishman that Time magazine had called the best novel ever written about Africa - and found it so false that he decided the story would have to be told from inside.

The novel gives an Igbo community a full internal life before the missionaries arrive: law, religion, agriculture, poetry, cruelty, and its own arguments. Okonkwo is not a noble victim - he is proud, violent and destroyed as much by his own rigidity as by the British. That refusal to make the pre-colonial world an idyll is a large part of why it has lasted.

Achebe also wrote the essay that permanently changed how Heart of Darkness is taught, calling Conrad a thoroughgoing racist and objecting that Africa functions in it as a backdrop for a European breakdown, with Africans given no language. He argued in English while defending the choice, on the grounds that the language had been given to him by history and he intended to use it on his own terms - a position other African writers, notably Ngugi wa Thiong'o, rejected by returning to their own languages.