The end of “Game of Thrones” is on the horizon, but creators David Benioff and D.B. Weiss have already mapped out their next plan at HBO for when they officially depart Westeros.

HBO has given a series order to “Confederate,” a new drama that hails from Benioff and Weiss, Variety has learned. The show has no ties to “Game of Thrones” and is not one of the many potential prequels in development at the network.

“Confederate” chronicles the events leading to the Third American Civil War. The series takes place in an alternate timeline, where the southern states have successfully seceded from the Union, giving rise to a nation in which slavery remains legal and has evolved into a modern institution. The story follows a broad swath of characters on both sides of the Mason-Dixon Demilitarized Zone – freedom fighters, slave hunters, politicians, abolitionists, journalists, the executives of a slave-holding conglomerate and the families of people in their thrall.

Production on “Confederate” will begin after the final season of “Game of Thrones.”

Season 7 of “Thrones” just began last weekend, premiering with record ratings. Season 8 is expected to debut in late 2018 or early 2019. Together, both seasons will span just 13 episodes.

Benioff and Weiss created “Confederate” and will serve showrunners, executive producers and writers, along with Nichelle Tramble Spellman (“Justified,” “The Good Wife”) and Malcolm Spellman (“Empire”), who will co-write the series and executive produce. “Game of Thrones” producers Carolyn Strauss and Bernadette Caulfield will also serve as executive producers.

“As the brilliant ‘Game of Thrones’ winds down to its final season, we are thrilled to be able to continue our relationship with Dan and David, knowing that any subject they take on will result in a unique and ambitious series,” said HBO programming president, Casey Bloys. “Their intelligent, wry and visually stunning approach to storytelling has a way of engaging an audience and taking them on an unforgettable journey. ‘Confederate’ promises to be no exception, and we are honored to be adding the talented team of Nichelle and Malcolm Spellman to the mix.”

“We have discussed ‘Confederate’ for years, originally as a concept for a feature film. But our experience on ‘Thrones’ has convinced us that no one provides a bigger, better storytelling canvas than HBO. There won’t be dragons or White Walkers in this series, but we are creating a world, and we couldn’t imagine better partners in world-building than Nichelle and Malcolm, who have impressed us for a long time with their wit, their imagination and their Scrabble-playing skills,” said Benioff and Weiss.

As for the “Game of Thrones” prequels that are in the works at HBO, Benioff and Weiss are not attached to any of the shows, so should any of those “Thrones” series get the greenlight, the duo’s focus will be on “Confederate.”

Benioff and Weiss are repped by CAA and Management 360.