9 Voyages is centered around Lord Corlys Velaryon, a.k.a. The Sea Snake, the Lord of the Tides and head of House Velaryon. Velaryon also appears in the previously announced House of the Dragon, in which he’s played by Steve Toussaint.
10,000 Ships is about warrior queen Princess Nymeria, an ancestor of House Martell who founded the kingdom of Dorne. Two characters in the original series, Sand Snake Nymeria Sand and Arya’s direwolf, bore her name. Her story is set roughly 1,000 years before Game of Thrones, so it takes place way before the Westeros timeline than any of the other previously announced projects in the works.
The third project is set in the Flea Bottom slum called King’s Landing, where characters like Davos Seaworth and Gendry Baratheon were born.
These prequels join the aforementioned House of the Dragon, which begins filming in April. Dragon takes place 300 years before the events in GoT and is based on Fire and Blood, George R.R. Martin’s recently published book about the history of the Targaryen house. Paddy Considine will play King Viserys Targaryen. He will be joined by Olivia Cooke (Alicent Hightower), Matt Smith (Prince Daemon Targaryen), and Emma D’Arcy (Princess Rhaenyra Targaryen).
The other GoT project reportedly in development is a prequel adaptation of Tales of Dunk and Egg. The one-hour episodic series will be based on George R.R. Martin’s fantasy novellas of the same name, which follow Ser Duncan the Tall (Dunk) and a young Aegon V Targaryen (Egg) on their adventures 90 years before the events of A Song of Ice and Fire.
“The way we try to approach it is not by [saying], ‘We need five shows within three years,’ but ‘What are the stories worth telling?'” HBO’s chief content officer Casey Bloys told THR in January. “We’ve been developing multiple takes on different worlds. The one I want to do is the one that I think is best creatively. I prefer to make it about the stories and the showrunners and their vision as opposed to hitting some arbitrary target for the right number of shows.”