House of the Dragon, HBO’s straight-to-series prequel to Game Of Thrones, is on track for a 2022 debut, HBO President of Programming Casey Bloys said in an interview with Deadline during TCA.

“My guess is sometime in 2022,” he said about when the series will premiere, stressing that it is too early to be more specific than that.

“They are starting writing,” Bloys said of the project from George R.R. Martin and Ryan Condal.

Written by Condal based on Martin’s Fire & Blood book, House of the Dragon is set 300 years before the events of Game of Thrones and tells the story of House Targaryen, rich in the dragonlord ancestors of Daenerys.

“Obviously it’s a big, complicated show,” Bloys said, adding that there is no casting news yet. GoT veteran Miguel Sapochnik and Condal have partnered as showrunners and serve as executive producers on House of the Dragon along with GoT co-executive producers Martin and Vince Gerardis.

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House of the Dragon was one of the four remaining GoT spinoffs in the works at HBO. The others are on hold, which could be indefinite — or temporary.

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“For me for right now, I think getting House of the Dragon on the air will be the number one priority,” Bloys said. “There are no other blinking green lights or anything like that. Sometime down the road who knows, but there are no immediate plans. We are all focusing on House of the Dragon.”

House of the Dragon was the second Game Of Thrones prequel to receive a green light, following a project written by Jane Goldman, which went to pilot starring Naomi Watts, but was not picked up to series. Bloys explained to Deadline why.

“In development, in pilots, sometimes things come together, sometimes they don’t,” he said. “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 (mothership) 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. That’s one of the reasons when we started out to think about ‘Is there a life after Game of Thrones in terms of Game of Thrones’, we purposefully developed multiple projects. 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.”