HBO promised a Game of Thrones prequel and the network has every intent to deliver.

House of the Dragon is officially in the production stage, according to a behind-the-scenes photo that went viral this week. HBO revealed the news with a picture of the cast doing a socially-distanced table read.

The prequel, from George R.R. Martin, Ryan Condal and Miguel Sapochnik, will star an all-new cast that includes Paddy Considine, Olivia Cooke, Matt Smith, Emma D’Arcy and Fabien Frankel, Deadline reports. Rhys Ifans, Steve Toussaint, Eve Best and Sonoya Mizuno will also feature, according to the site.

“Based on Martin’s Fire & Blood, the series, which is set 300 years before the events of Game of Thrones, tells the story of House Targaryen. Considine plays King Viserys Targaryen, Cooke stars as Alicent Hightower, D’Arcy as Princess Rhaenyra Targaryen, Smith as Prince Daemon Targaryen and Toussaint as Lord Corlys Velaryon, known as the Sea Snake, who becomes Hand to Queen Rhaenyra Targaryen during the Dance of the Dragons,” Deadline states. Check out the BTS photo that’s got everyone talking up top.

Prior to House of the Dragon, HBO planned on a different prequel — Age of Heroes — but that one was canceled because it wasn’t well-received by executives. More details on that here, if you missed the reports.

House of the Dragon has a debut timetable of 2022. Stay tuned, as we’ll continue to update you with more information on the series as it becomes available.