Lyanna Stark on ‘Game of Thrones’: Theories & Analysis

Lyanna Stark is Ned's sister and a mysterious character in Game of Thrones. For years, her character has held the key to a fan-favorite theory that involves the Tower of Joy. Despite being long dead by the time the series starts, she's actually a central figure to the storyline's future. This is everything you need to know about Lyanna, but the post will also include spoilers through the season 6 finale. Click through the gallery to learn more about Lyanna, including what was revealed tonight. (HBO)