In 2007, director Zack Snyder brought graphic novelist Frank Miller's book 300 to life on the big screen. The film, while receiving mixed reviews from film critics, was a major success with the general audiences, many of which felt that the film made being macho cool again.
The film told the story of the legendary Battle of Thermopylae, where 300 Spartans, including their king Leonidas, stood against the massive Persian army, which is theorized to have had as many as ten thousand to one million soldiers. It is considered a classic tale of an underdog story, as the 300 soldiers gave their lives to buy the rest of Sparta time to evacuate.
The film was very well received by general audiences and became a pop culture phenomenon, spurring everything from youtube videos to tattoos to parodies to even a diet program to gain the physique that the actors had to achieve to be believable as Spartans. The film's major success led many to wonder whether or not a sequel would be done, but there were several problems with that.
One problem was that it was unclear whether or not the sequel would take place directly after the first film or if it would be more of a spiritual successor to the original story. Another problem was that there was no sequel to the graphic novel, and as the film was an almost word for word adaptation of the graphic novel, it could be problematic to make up a story without the vision of Frank Miller. However, it seems that those problems may be moot after all, as director Zach Snyder announced that the sequel film would not be made until there was a sequel to the graphic novel. Frank Miller soon followed saying that he had found a subject for a sequel to the graphic novel.
There is currently no word on what exactly the new graphic novel is about, but Snyder has stated that the stuff he has seen from the new book appears to be bigger than the first one, but that he has advised Miller not to alter his ideas for the book just to make it more filmable and that they want a good book to base the movie on, and not a book based on the fact that a film would be made.
There is currently no release date for either the graphic novel or the film, but it is rumored to be expected within the next five years.