This was when the first film came out, approximately 15 years ago (2001) - Harry Potter and the Philosopher´s Stone. Unfortunately, Daniel Radcliffe could not attend. For all americans wondering why I wrote "Philosopher´s Stone" and not "Sorcerer's stone": "Philospher" = The original, British title. "Sorcerer" = The American title. They had to change the title since they were concerned that Americans would not understand what a Philosopher is, given that it isn't the same in the US as it is in England. This has though led to criticism as some think that the title change might have insulted the American citizen's intelligence. Rowling opposed that idea. But since this was her first book, she didn't dare to stand up to the American publisher.