HBO
Just like many deaths on the show, it seems one Game of Thrones prequel isn't going to see the light of day—at least according to rumours. The prequel in question is the one written by Jane Goldman and starring Naomi Watts. It was supposed to take place thousands of years before Game of Thrones. HBO hasn't confirmed that the project has been canned, but Goldman is reportedly reaching out to the cast and crew informing them that the pilot is dead. The project first got green-lit back in June 2018, where it was chosen among other prequel scripts that were commissioned by HBO. Reports claim there were issues during filming in Northern Ireland, but it is unclear if this is the cause of the cancellation.
Back in September, HBO reportedly green-lit another prequel that follows the House of Targaryen. This one takes place 300 years before the main series.
Source: Deadline