LOS ANGELES (REUTERS) - The creators of HBO's hit medieval fantasy Game of Thrones have their next show lined for the premium cable network, but this one has no dragons or an undead army of white walkers.

David Benioff and Dan Weiss, who adapted Game of Thrones from George R.R. Martin's A Song of Ice and Fire books, will write and direct original series Confederate, HBO said on Wednesday.

The show is set in an alternative reality in a nation where slavery is still legal and southern US states have seceded. HBO said the series "chronicles the events leading to the Third American Civil War." It will explore perspectives including freedom fighters, slave hunters, politicians, journalists and abolitionists on both sides of the divide, HBO said in a statement. Confederate is a world away from the dragons, undead armies and magic in the medieval setting of Game of Thrones,where warring factions scheme and battle for control over the Seven Kingdoms of Westeros.

Benioff and Weiss said they had initially conceivedConfederate as a feature film but their success with Game of Thrones had "convinced us that no one provides a bigger, better storytelling canvas than HBO." No further details were given on the new show, casting or when it is scheduled to air.

The announcement comes as Benioff and Weiss head into the final season of Game of Thrones, scheduled to conclude next year. The show's seventh season premiered with record ratings on Sunday, drawing some 16.1 million US viewers, HBO said.