The series Tales of Dunk & Egg includes three novellas: The Hedge Knight, The Sworn Sword, and The Mystery Knight. They follow the adventures of Ser Duncan the Tall (Dunk) and a young Aegon V Targaryen (Egg). The novellas are set about 90 years before the events of Game of Thrones.
According to Variety, the project is in the early stages of development, and no writer has not been attached yet. Martin and HBO have declined to comment on the news.
HBO had multiple Game of Thrones prequels in development in 2017. That included a Naomi Watts-led prequel known as The Long Night, which was nixed after it filmed a pilot.
One of those projects will reach the small screen. House of the Dragon is moving forward and is expected to air in 2022. The series will document the buildup to the Targaryen civil war known as the Dance of Dragons.
Fans of Game of Thrones have been calling for an adaptation of Tales of Dunk & Egg for some time. However, previously it seemed unlikely since it wasn’t among the prequel ideas HBO announced in 2017. Also, Martin himself said that there were no plans to adapt the books at that time.