As per a report in The Hollywood Reporter, one of the spin-offs will concentrate on the origins and the downfall of the Targaryen empire. The setting befalls 300 years before the happenings of Game of Thrones. Furthermore, it is said that Ryan Condal, along with 'Game Of Thrones' writer George RR Martin, will write the script for the prequel, which is based on Martin's book "Fire and Blood".
The tale starts with Aegon the Conqueror, who was the founder and first king of the Targaryen dynasty when he vanquished all of Westeros and united the domain (except for Dorne and the terrains past the Wall) with three extraordinary winged serpents, Balerion, Vhagar and Meraxes. He was hitched to both of his sisters, Visenya and Rhaenys. He was formally styled as Aegon of House Targaryen, the First of His Name, King of the Andals and the First Men, Lord of the Seven Kingdoms, and Protector of the Realm. Popular GOT characters such as Danaerys Targaryen and Jon Snow were the descendants of this once a great family.