HBO released these animated extras to the GAME OF THRONES season 5 Blu-ray, They don’t talk about it as much in the series as much as they do in the books. Honestly, I think the story of the fall of the Targaryens is more interesting than the events of Game of Thrones, This preview features Sir Barristan Selmy recalling his role in Robert’s Rebellion.
https://youtu.be/kpt-XEnhzJ4
Source Gizmodo.