A little over 300 years prior to the events of Thrones season 8 , Westeros was a sprawling continent run by various warring factions led by different kings. Then, Jon's true namesake Aegon Targaryen decided to bring each and every one of those fiefdoms to heel under his rule. At the time, the Targaryens were relative newcomers to Westeros, who fled their original home, the great holdfast of Valyria, 12 years ahead of the Doom . As we see in season 5’s “Kill The Boy,” Valryia was a technologically and culturally advanced society that was brutally devastated by an unknown, fiery cause.