HBO expands on why Game of Thrones prequel was scrapped

A pilot episode was written and produced by Jane Goldman (Kingsman), set thousands of years before the original fantasy epic and starring Naomi Watts (The Loudest Voice) in the lead role.

However, HBO opted to pull the plug on the potential series, instead choosing to move forward with a different prequel titled House of the Dragon.

Casey Bloys, President of HBO Programming, told Deadline: "One of the things I think Jane took on beautifully, which was a challenge, there was a lot more world creation because she set hers 8,000 years before the [original] show, so it required a lot more.

"That is a big swing. One of the things about House of Dragons, there is a text, there is a book so that made it a little bit more of a road map for a series order. I think Jane did a beautiful job, it was a big challenge but there was nothing that I would point to and say, oh, that one element did not work, just overall it did not quite gel."

He added: "We would have been very lucky to do one pilot, have that pilot go and be a success but in development as you know, it takes a lot of tries to get it right. This is no different."

House of the Dragon will draw from George R.R. Martin's novel Fire & Blood, which reveals more about the history of the Targaryens.

In the same interview, Bloys estimated that the series could make it to television "sometime in 2022."