'Game of Thrones' Writer Bryan Cogman Developing Fifth Prequel

Four prequels were announced in May, with George R.R. Martin co-writing with two of the four

Four 'Game of Thrones' prequels were announced in May, with book author George R.R. Martin co-writing with two of the four. Credit: Frederick M. Brown/Getty

A fifth Game of Thrones prequel is confirmed to be in the works, with veteran writer and co-executive producer Bryan Cogman at the helm.

As reported by Entertainment Weekly, Cogman has been working closely with author George R.R. Martin to develop the project, which will join four prequels previously announced this past May.

Cogman has been involved with HBO's Game of Thrones series since the very first season, initially hired as an assistant to show runners David Benioff and Dan Weiss. He has since written numerous episodes, including several of the series' most standout: "The Laws of Gods and Men," "Kissed by Fire" and "Stormborn."

And though specifics about the project's plot are sparse, Entertainment Weekly notes that Martin has ruled out any storylines dealing with Robert's Rebellion (since the majority of fans already know the major plot points of that war anyway) and his Dunk & Egg tales (which he is currently still writing).

Outside of those two stipulations, anything goes, given that Cogman's prequel project – as well as the four other writers' – will be set in a time period that takes place prior to the events depicted on Game of Thrones. (This also suggests that none of the current cast will appear in any of the prequels).

Martin hinted at Cogman's fifth prequel in a post to his LiveJournal page this past May. "We had four scripts in development when I arrived in L.A. last week, but by the time I left we had five," he wrote at the time.

The other four writers announced by HBO earlier that month include Max Bortstein (Kong: Skull Island), Jane Goldman (Kingsman: The Golden Circle), Brian Helgeland (A Knight's Tale, Robin Hood) and Carly Wray (Mad Men, The Leftovers). Martin will co-write with Goldman and Wray.

In June, HBO president of programming Casey Bloys clarified that while the network will consider all four, now-five, projects, none are guaranteed a green light.

"The bar set … is so high that my hope is to get one show that lives up to it," Bloys said at the time. Game of Thrones is set to end its eight-season run sometime in 2018 or 2019; the earliest fans can expect any prequels would be 2019.

Meanwhile, both Benioff and Weiss will take a step back from the Westeros world. The show runners announced in July that they are developing a controversial alt-history drama, Confederate, for HBO.