Various sources have recently claimed that HBO is working on multiple "Game of Thrones" spin-offs and has already hired four renowned writers to work on them. George R.R. Martin, the creator of the "Song Of Ice And Fire" series, was also rumored to be involved in these projects.

Martin has now officially confirmed that HBO is, in fact, working on five spin-offs and that he has been involved in these projects for months now. On his LiveJournal blog, the author further revealed significant details, including what the spin-offs won't be about.

Martin prefers to call the spin-offs 'successor shows'

According to Martin, the spin-offs are all prequels, meaning that the stories will be taking place before the events in "Game of Thrones." However, the author says that he prefers to use the term "successor show" to refer to these spin-offs.

"Every one of the concepts under discussion is a prequel, rather than a sequel," said Martin on his blog. Furthermore, Martin revealed that he initially pitched two possible series to HBO, with one of these concepts currently in development.

Five spin-offs instead of four

The author further confirmed that the writers currently working on these projects are Max Borenstein, Jane Goldman, Brian Helgeland, and Carly Wray, as previously reported by various news outlets.

While Martin was initially rumored to be working with only two of these writers, the creator of the "Song of Ice and Fire" novels claimed that he's been, in fact, working with all four.

Moreover, there will be an additional spin-off, as Martin revealed that HBO has hired a fifth writer, who remains unnamed at this time, to work on another project set in the world of "Game of Thrones."

The 'successor shows' won't be about Robert's Rebellion

To the dismay of many "Game of Thrones" fans, Martin announced that the spin-offs won't be about Robert's Rebellion or the "Dunk and Egg" novels.

And while this may be bad news for many who have been hoping to see Robert Baratheon and Eddard Stark fighting side by side, Martin has his reasons.

Regardless, Martin seems open to the possibility of eventually bringing the "Dunk and Egg" stories to television, but he insists on finishing the novels first. Robert's Rebellion, on the other hand, won't ever be a TV show, according to the novelist.

"By the time I finish writing A SONG OF ICE & FIRE, you will know every important thing that happened in Robert's Rebellion," said Martin.

As such, Martin believes that a show about the great rebellion would be redundant, since there wouldn't be any surprises or revelations left to tell in a TV adaptation. Still, many fans would probably love to see Robert's Rebellion come to life on the small screen.