HBO expands on why Game of Thrones prequel was scrapped

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."