Reportedly still on the drawing board since at least January 2021, Dunk and Egg — based on Martin’s Tales of Dunk and Egg series of novellas — would follow Dunk, a.k.a. future Kingsguard Lord Commander Ser Duncan the Tall, and his squire Egg, a.k.a. the future king Aegon V Targaryen and great-grandfather of Daenerys. in their exploits nearly a century before the events of Game of Thrones.
Dunk and Egg: In development