Jane Goldman's untitled Game of Thronesprequel pilot was not picked up for series at HBO, according to The Hollywood Reporter.

The pilot, which would have taken place thousands of years before the events of Game of Thrones during its legendary "Age of Heroes," finished filming in the summer of 2019. THRreports that Goldman e-mailed the pilot's cast including Naomi Watts, Jamie Campbell-Bower, and Naomi Ackie to tell them that HBO passed on the series. They also report that the pilot was potentially not up to par at the network, citing sources that "say HBO wasn't thrilled with the final cut of the Watts-led pilot and asked for changes in edits before scrapping the entire thing."

The Age of Heroes prequel, which George R.R. Martin consulted on and referred to as "The Long Night" on his blog, was likely about with the first invasion of the White Walkers and the state of Westeros 10,000 years before the events of Game of Thrones.

While declining to order a prequel to what was arguably the most successful television show of all time seems like a shocking move, there is still another Thronesprequel in the works at HBO. This prequel, allegedly about the Targaryen conquest of Westeros and based on George R.R. Martin's Fire and Blood, would take place only 300 years before the show. No casting information about that prequel has been announced.