Franz Kafka's works were published after his death by his friend and literary executor, Max Brod. When Kafka was very ill, he wrote a letter to his friend where he said that he was leaving all his work to him and that he wanted him to destroy them after he was gone.
But Brod ignored him and published his works anyway. When Brod published his works, the name and work of Franz Kafka gained worldwide posthumous fame. And today, thanks to Brod's efforts, Kafka is one of the most original writers of the 20th century.
In his book "Franz Kafka, a Biography" from 1937, Brod explains how he couldn't do what his friend wanted, ignoring Kafka's request and publishing his novels.