HBO is close to ordering a pilot for a Game of Thrones spin-off that would focus on House Targaryen. Deadline reports that it is a prequel series from A Song of Ice and Fire author George R. R. Martin, who also served as co-executive producer on the Game of Thrones series it inspired. Colony co-creator and executive producer Ryan Condal is also said to be involved as co-creator and writer.

Deadline reports that the spin-off will be set 300 years before the events of Game of Thrones and will chart the "beginning of the end for House Targaryen." It is said to be based on Fire & Blood, which was written by Martin, and has been in the works since last fall.

This show is not believed to be one of the five Game of Thrones spin-offs planned by HBO, but began as an idea for that group. The Targaryan spin-off is "a brand new take on a world originally tackled by Bryan Cogman in one of the five GoT prequel scripts commissioned by HBO in 2017," Deadline's report reads.

HBO has not yet officially acknowledged or confirmed the report.

Currently, the only Game of Thrones spin-off that has been officially confirmed is what Martin called "The Long Night," before backtracking on the name later. Naomi Watts has been cast in the show, which takes place thousands of years before Game of Thrones. Watts' character is said to be "a charismatic socialite hiding a dark secret."