Franz Kafka lived in Prague, Czechoslovakia, as part of the German speaking minority. As he always wrote in German, he is generally considered to be a German writer.
His nightmarish prose 'The Trial', 'The Metamorphosis', 'The Castle' and other miniatures and fragments are haunting examples of expressionist literature.
His style is so consistent and unique, yet unsettling and hilarious at the same time, that it has become its own brand: 'Kafkaesque'.
Most of his prose was published posthumously by his lifelong friend Max Brod.