“A Song of Ice and Fire” author George R. R. Martin has posted an excerpt from his upcoming companion book “The World of Ice and Fire: The Untold History of Westeros and the World of Game of Thrones” on his official website.

What’s most intriguing though is that it includes an illustration of the character Aegon the Conqueror riding on top of his dragon Balerion the Black Dread. The pic effectively demonstrates how big Daenerys Targaryen’s continually growing dragons will get when they reach full adulthood.