Harry Potter (book series 1997 - 2007, film series 2001 - 2011)
The Harry Potter series is a fantasy book and film series, based on the titular character studying at Hogwarts School of Witchcraft and Wizardry. Both the book and film series have gone on to become the highest grossing series' in their respective mediums. It focuses on Potter's quest to stop the Dark Lord Voldermort from taking over the wizarding world and wiping out all of those that cannot use magic. The original concept for the series was thought up by writer J. K. Rowling while delayed for four hours on a train ride in 1990. Due to the popularity of the novels and film series, J. K. Rowling now has a net worth of 1 billion USD.
While the book series consisted of seven book, the film series contained eight movies. This is because, as the general public had become so connected to the world of the films, the final movie was split into two part - one wound down the world of the films, and the other provided the final climax of the series. The films are known for, amongst other things, their cast of some of the most famous British actors, as part of J. K. Rowling's contract that the films would only contain British actors for British parts. As well as launching the careers of Daniel Radcliffe, Rupert Grint and Emma Watson, the films contained Helena Bonham Carter, John Cleese, Robbie Coltrane, Warwick Davis, Ralph Fiennes, Michael Gambon, Brendan Gleeson, Richard Griffiths, Gary Oldman, Alan Rickman, Maggie Smith, David Thewlis and Emma Thompson, among many others.