Which Harry Potter book did J.K. Rowling say she conceived on a train to London?

J.K. Rowling conceived Harry Potter and the Philosopher’s Stone during a train journey to London in 1990.

Rowling later described seeing the idea of a boy who did not know he was a wizard while travelling from Manchester to London. She did not have a pen available, so she spent much of the journey imagining details and characters. The train-journey origin became one of the best-known parts of the series’ creation story.

The idea developed for years before publication. Rowling wrote substantial parts of the manuscript, experienced personal and financial difficulties, and eventually found an agent and publisher. Bloomsbury released the finished novel in 1997, seven years after the journey she identified as the story’s starting point.

The train itself also became an important image in the books. Harry travels to Hogwarts on the Hogwarts Express, departing from Platform 9¾ at London’s King’s Cross station. That fictional railway journey echoes, but does not reproduce, the author’s real-life inspiration.