HBO is reportedly close to green-lighting a Game of Thrones prequel series based on the history of the Targaryens.

According to EW, the series will specifically chronicle the Dance of the Dragons, a.k.a. the civil war between Rhaenyra and Aegon Targaryen for control over the Seven Kingdoms. The war occurred roughly 200 years before the events depicted in Game of Thrones.

The series’ plot will pull from Fire and Blood, George R.R. Martin’s recently published book about the history of the Targaryen house. Ryan Condal is said to be writing the pilot episode, and Martin is on board as an executive producer.

The as-yet-untitled series marks the second Game of Thrones prequel ordered by HBO. Already in development is a prequel series set 5,000 years in the past, created by Jane Goldman and starring Naomi Watts, Naomi Ackie, and Jamie Campbell Bower, among others.

When HBO first began mapping out its post-Game of Thrones plans, the network hired as many as five different writers to each develop a different spin-off that would “explore different time periods of George R. R. Martin’s vast and rich universe.” In a blog past earlier this year, Martin revealed that two of those projects were “still moving forward nicely” in addition to Goldman’s series.

Presumambly, Fire and Blood is the one of those series; there’s no word on what the second project may entail or if it’s even still in development. HBO head Casey Bloys previously said there was no guarantee that the various GOT offshoots would all make it to air. “The idea is not to do four shows [or five]. The bar set by [David Benioff and DB Weiss] is so high that my hope is to get one show that lives up to it.”

In the meantime, fans can catch the latest leg of the “Game of Thrones Live Concert Experience”, which runs until early October. You can get tickets to the upcoming dates here.