Through A Song of Ice and Fire and Fire & Blood, George R. R. Martin has created a world so rich in history that it feels almost real. The known world that Westeros and Essos are a part of goes back thousands of years, from the First Men and Children of the Forest to the War of the Five Kings. One of the main events of Westeros was the Dance of the Dragons, depicted in Fire & Blood and upcoming seasons of House of the Dragon.
Source:https://www.cbr.com/game-of-thrones-reference-house-of-the-dragon/