We Legitimately Forgot How Many Important Characters Die in Game of Thrones Season 1

The death that started the battle between Houses Lannister and Stark, Jon Arryn's death happens off screen in episode one, but it 's a major death in Game of Thrones nonetheless. After Jon's death, Catelyn Stark receives a message from her sister, Lysa, accusing the Lannisters of killing her husband. It's revealed in later seasons that Lysa poisoned her own husband at the request of Petyr Baelish.