Here is a link to a lead in trailer for ... The House of Dragons ... and warning: there are lots spoilers here ...
https://www.youtube.com/watch?v=Ts2j8L7p2FoIt seems the new series coming in 2022 is based on George R.R. Martin's book called "Fire and Blood" which is set 300 years before the events of Game of Thrones. Although apparently there are two other works he has written, "The Princess and the Queen, or the Blacks and the Greens", and "A Rogue Prince, or a King's Brother", that both also include parts told in the upcoming show.
There are rumors that there are a few other series being planned for this fantasy world as well.
