The cast of Harry Potter: then and now David Edwards When you think of the most popular book and movie franchise of all time, one name comes to mind: Harry Potter. It has become a cultural phenomenon around the globe and has truly changed the world. The first book series was written by J.K. Rowling and the first book, J.K. Rowling was traveling on a train from Manchester to London when she originally thought of the idea for the seven-book series. In an excerpt of J.K. Rowling speaks of her clear vision of the book that she felt on that train